Catheter blood pumps and collapsible pump housings

ABSTRACT

Catheter blood pumps that include an expandable pump portion. The pump portions include an collapsible blood conduit that defines a blood lumen. The collapsible blood conduits include a collapsible scaffold adapted to provide radial support to the blood conduit. The pump portion also includes one or more impellers.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Prov. App. No. 62/905,985,filed Sep. 25, 2019, the entire disclosure of which is incorporated byreference herein for all purposes.

INCORPORATION BY REFERENCE

All publications and patent applications mentioned in this specificationare herein incorporated by reference to the same extent as if eachindividual publication or patent application was specifically andindividually indicated to be incorporated by reference.

BACKGROUND

Patients with heart disease can have severely compromised ability todrive blood flow through the heart and vasculature, presenting forexample substantial risks during corrective procedures such as balloonangioplasty and stent delivery. There is a need for ways to improve thevolume or stability of cardiac outflow for these patients, especiallyduring corrective procedures.

Intra-aortic balloon pumps (IABP) are commonly used to supportcirculatory function, such as treating heart failure patients. Use ofIABPs is common for treatment of heart failure patients, such assupporting a patient during high-risk percutaneous coronary intervention(HRPCI), stabilizing patient blood flow after cardiogenic shock,treating a patient associated with acute myocardial infarction (AMI) ortreating decompensated heart failure. Such circulatory support may beused alone or in with pharmacological treatment.

An IABP commonly works by being placed within the aorta and beinginflated and deflated in counterpulsation fashion with the heartcontractions, and one of the functions is to attempt to provide additivesupport to the circulatory system.

More recently, minimally-invasive rotary blood pumps have been developedthat can be inserted into the body in connection with the cardiovascularsystem, such as pumping arterial blood from the left ventricle into theaorta to add to the native blood pumping ability of the left side of thepatient's heart. Another known method is to pump venous blood from theright ventricle to the pulmonary artery to add to the native bloodpumping ability of the right side of the patient's heart. An overallgoal is to reduce the workload on the patient's heart muscle tostabilize the patient, such as during a medical procedure that may putadditional stress on the heart, to stabilize the patient prior to hearttransplant, or for continuing support of the patient.

The smallest rotary blood pumps currently available can bepercutaneously inserted into the vasculature of a patient through anaccess sheath, thereby not requiring surgical intervention, or through avascular access graft. A description of this type of device is apercutaneously-inserted ventricular support device.

There is a need to provide additional improvements to the field ofventricular support devices and similar blood pumps for treatingcompromised cardiac blood flow.

SUMMARY OF THE DISCLOSURE

The disclosure is related to intravascular blood pump and their methodsof and manufacture.

One aspect of this disclosure is a pressure sensor carrier. The pressuresensor carrier may be secured to a pump portion of an intravascularblood pump, which may include a collapsible blood conduit and one ormore collapsible impellers at least partially disposed within thecollapsible blood conduit. The pressure sensor carrier may include acarrier body that is configured to receive therein at least a portion ofa pressure sensor, and optionally one or more sensor connections thatare coupled to the pressure sensor and extending proximally therefrom.The pressure sensor carrier may have one or more inner surfaces thatdefine a channel, recessed region, depression, or other open area orspace configured to receive the sensor and optionally one or moreconnections therein. A stabilizing material may be disposed at leastpartially about the sensor and optionally about the one or moreconnections to help stabilize the sensor within and relative to thecarrier body.

In this aspect, the pressure sensor carrier may include a carrier bodythat includes a recessed region in a first side of the carrier body.

In this aspect, a pressure sensor may be secured at least partiallywithin a carrier recessed region such that a pressure sensitive face isfacing outward relative to the carrier body.

In this aspect, one or more sensor connections that are coupled to, incommunication with, and extending proximally from the pressure sensormay be secured within a recessed region of the pressure sensor carrierbody.

In this aspect, a stabilizing or encapsulating material may be disposedat least partially in a recessed region of the carrier body and aboutthe pressure sensor and the one or more connection to help stabilize thepressure sensor and the one or more sensor connections relative to thecarrier body.

In this aspect, the pressure sensor carrier may be secured distal to adistal end of the collapsible blood conduit.

In this aspect, the pressure sensor carrier may be secured to anon-expandable distal end portion of the pump portion, such asnon-expandable cylindrically configured component.

In this aspect, one or more sensor connections may be secured to anexpandable distal strut that extends distally from a distal end of thecollapsible blood conduit.

In this aspect, one or more sensor connections may be disposed radiallyoutward relative to the distal strut. In this aspect, one or more sensorconnections may be secured to the collapsible blood conduit.

In this aspect, one or more sensor connections may be secured to anouter surface of the collapsible blood conduit.

In this aspect, one or more sensor connections may not extend radiallywithin the collapsible blood conduit.

In this aspect, a recessed region of a carrier body may include a distalrecess region and a proximal recess region, where the distal recessregion at least partially surrounds the pressure sensor, a and where thedistal recess region has a width that is greater than the proximalrecess region, wherein one or more connections may be secured anddisposed in the proximal recess region.

In this aspect, the pressure sensor carrier may be secured to the pumpportion such that the pressure sensitive face faces radially outward,optionally facing in a direction that is orthogonal to a long axis ofthe pump portion.

One aspect of the disclosure is an intravascular blood pump comprising apump portion. The pump portion may include a collapsible blood conduit,a plurality of distal struts extending distally from the collapsibleblood conduit, wherein distal ends of the distal struts may be securedto a distal end portion of the pump portion that is disposed about along axis of the pump portion, the collapsible blood conduit having anexpanded configuration with a radially outermost dimension greater thana radially outermost dimension of the distal end portion. The pumpportion may include a pressure sensor secured to the distal end portion,the pressure sensor having a pressure sensitive region positioned suchthat it is exposed to a flow of blood moving toward an inflow of thepump portion. The pump portion may include one or more collapsibleimpellers at least partially disposed within the collapsible bloodconduit.

This aspect may further comprise a pressure sensor connection orconnector coupled to the sensor and in communication with the pressuresensor, wherein the pressure sensor connector extends proximally fromthe pressure sensor and is secured or coupled to a first strut of theplurality of distal struts.

In this aspect, a pressure sensor connector or connection may comprise awire.

In this aspect, a pressure sensor connector may be coupled to a radiallyouter surface of a first strut.

This aspect may further comprise a pressure sensor connector orconnection housing in which a pressure sensor connector or connection isdisposed, the pressure sensor connector housing coupled to a radiallyouter surface or a radially inner surface of a first strut.

In this aspect, a pressure sensor connector may be secured to a firststrut such that the pressure sensor connector is configured to movetowards a collapsed state when the blood conduit is collapsed, andwherein the sensor is secured to the distal end portion such that itdoes not move radially when the blood conduit is collapsed to acollapsed configuration.

In this aspect, a pressure sensitive face of the pressure sensor isfacing radially outward in a direction orthogonal to a long axis of thepump portion.

This aspect may further include a pressure sensor housing in which atleast a portion of the pressure sensor is disposed, the pressure sensorhousing secured to the distal end portion.

In this aspect, the distal end portion may comprise a distal bearinghousing that is disposed distal to the blood conduit.

In this aspect, the pressure sensor may be secured to a cylindricalcomponent.

In this aspect, the pressure sensor may be secured within a pressuresensor carrier, such as any of the pressure sensor carriers described orclaimed herein.

This aspect may further comprise a collapsible impeller housingcomprising the collapsible blood conduit and the plurality of struts,wherein a pressure sensitive surface of the pressure sensor is disposedaxially outside of the collapsible impeller housing.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of an exemplary expandable pump portion thatincludes an expandable impeller housing that includes a scaffold andblood conduit, and a plurality of impellers.

FIG. 2 is a side view of an exemplary expandable pump portion thatincludes an expandable impeller housing, a blood conduit, a plurality ofimpellers, and a plurality of expandable scaffolds sections or supportmembers.

FIGS. 3A, 3B, 3C and 3D illustrate an exemplary expandable pump portionthat includes a blood conduit, a plurality of impellers, and a pluralityof expandable scaffold sections or support members.

FIG. 4 illustrates an exemplary target location of an expandable pumpportion, the pump portion including a blood conduit, a plurality ofexpandable scaffold sections or support members, and a plurality ofimpellers.

FIG. 5 illustrates an exemplary pump portion including an expandableimpeller housing, a blood conduit, and a plurality of impellers.

FIG. 6A illustrates at least a portion of an exemplary catheter bloodpump that includes a pump portion, wherein at least two differentimpellers can be rotated at different speeds.

FIG. 6B illustrates at least a portion of an exemplary catheter bloodpump that includes a pump portion, where at least two differentimpellers can be rotated at different speeds.

FIG. 6C illustrates at least a portion of an exemplary catheter bloodpump that includes a pump portion with at least two impellers havingdifferent pitches.

FIG. 7 illustrates a portion of an exemplary catheter blood pump thatincludes a pump portion.

FIG. 8 illustrates an exemplary expandable pump portion including aplurality of expandable impellers, including one or more bends formedtherein between adjacent impellers.

FIG. 9 illustrates an exemplary expandable pump portion comprising aplurality of impellers and a blood conduit.

FIG. 10 illustrates an exemplary scaffold design and exemplary struts.

FIG. 11 illustrate an exemplary scaffold design and exemplary struts.

FIGS. 12A-12F illustrate an exemplary sequence of steps that may beperformed to deploy an exemplary pump portion of a catheter blood pump.

FIGS. 13A and 13B illustrate exemplary portions of an expandable pumpportion.

FIG. 13C illustrates a scaffold from FIGS. 13A and 13B shown in aflattened and non-expanded configuration, as well as optional distal andproximal struts extending axially therefrom.

FIG. 14A illustrates an exemplary expanded scaffold that may be part ofany of the expandable pump portions herein.

FIG. 14B illustrates the scaffold and struts from FIG. 14A in aflattened and non-expanded configuration.

FIG. 15A illustrates an exemplary expanded scaffold that may be part ofany of the expandable pump portions herein.

FIG. 15B illustrates the scaffold and struts from FIG. 15A in aflattened and non-expanded configuration.

FIG. 16 illustrates an exemplary scaffold and optionally coupled strutsin a flattened and non-expanded configuration.

FIG. 17 illustrates an exemplary scaffold and optionally coupled strutsin a flattened and non-expanded configuration.

FIG. 18A illustrates an exemplary scaffold in a flattened andnon-expanded configuration.

FIG. 18B illustrates the scaffold from FIG. 18A in an expandedconfiguration.

FIG. 19A illustrates an exemplary scaffold in a flattened andnon-expanded configuration.

FIG. 19B illustrates the scaffold from FIG. 19A in an expandedconfiguration.

FIG. 20A illustrates an exemplary scaffold in a flattened andnon-expanded configuration.

FIG. 20B illustrates the scaffold from FIG. 20A in an expandedconfiguration.

FIG. 21A illustrates an exemplary scaffold in a flattened andnon-expanded configuration.

FIG. 21B illustrates the scaffold from FIG. 21A in an expandedconfiguration.

FIG. 22A illustrates an exemplary scaffold in a flattened andnon-expanded configuration.

FIG. 22B illustrates the scaffold from FIG. 22A in an expandedconfiguration.

FIG. 23A illustrates an exemplary scaffold in a flattened andnon-expanded configuration.

FIG. 23B illustrates the scaffold from FIG. 23A in an expandedconfiguration.

FIG. 24A illustrates an exemplary scaffold in a flattened andnon-expanded configuration.

FIG. 24B illustrates the scaffold from FIG. 24A in an expandedconfiguration.

FIG. 25A illustrates an exemplary scaffold in a flattened andnon-expanded configuration.

FIG. 25B illustrates the scaffold from FIG. 25A in a flattened expandedconfiguration.

FIG. 26A illustrates an exemplary scaffold in a flattened andnon-expanded configuration.

FIG. 26B highlights an exemplary section of the scaffold shown in FIG.26A.

FIG. 27A illustrates an exemplary scaffold in a flattened andnon-collapsed configuration.

FIG. 27B illustrates the scaffold from FIG. 27A in a non-collapsedconfiguration.

FIG. 28 is a side view of an exemplary pump portion that includes asensor wire.

FIG. 29 is a cross sectional view of an exemplary expandable impellerhousing that includes a sensor connector fixed to the expandableimpeller housing.

FIG. 30 is a cross sectional view of an exemplary expandable impellerhousing that includes a sensor connector disposed in a sensor wirelumen.

FIG. 31 is a cross sectional view of an exemplary expandable impellerhousing that includes a sensor connector disposed in a sensor wirelumen.

FIG. 32 is a cross sectional view of an exemplary expandable impellerhousing that includes a sensor connector disposed in a sensor wirelumen.

FIG. 33 is a side view of an exemplary pump portion that includes asensor connector carried by and outside of an expandable impellerhousing, the pump portion including a sensor coupled to the sensor wire.

FIG. 34A illustrates a region of an exemplary pump portion that includesa pressure sensor carrier or housing with a pressure sensor securedrelative thereto.

FIG. 34B illustrates an exemplary sensor carrier or housing with anexemplary sensor secured relative thereto.

DETAILED DESCRIPTION

The present disclosure is related to medical devices, systems, andmethods of use and manufacture. Medical devices herein may include adistal pump portion (which may also be referred to herein as a workingportion) adapted to be disposed within a physiologic vessel, wherein thedistal pump portion includes one or more components that act upon fluid.For example, pump portions herein may include one or more rotatingmembers that when rotated, can facilitate the movement of a fluid suchas blood.

Any of the disclosure herein relating to an aspect of a system, device,or method of use can be incorporated with any other suitable disclosureherein. For example, a figure describing only one aspect of a device ormethod can be included with other embodiments even if that is notspecifically stated in a description of one or both parts of thedisclosure. It is thus understood that combinations of differentportions of this disclosure are included herein.

FIG. 1 is a side view illustrating a distal portion of an exemplarycatheter blood pump, including pump portion 1600, wherein pump portion1600 includes proximal impeller 1606 and distal impeller 1616, both ofwhich are in operable communication with drive cable 1612. Pump portion1600 is in an expanded configuration in FIG. 1, but is adapted to becollapsed to a delivery configuration so that it can be delivered with alower profile. The impellers can be attached to drive mechanism 1612(e.g., a drive cable). Drive mechanism 1612 is in operable communicationwith an external motor, not shown, and extends through elongate shaft1610. The phrases “pump portion” and “working portion” (or derivativesthereof) may be used herein interchangeably unless indicated to thecontrary. For example without limitation, “pump portion” 1600 can alsobe referred to herein as a “working portion.”

Pump portion 1600 also includes expandable member or expandable scaffold1602, which in this embodiment has a proximal end 1620 that extendsfurther proximally than a proximal end of proximal impeller 1606, and adistal end 1608 that extends further distally than a distal end 1614 ofdistal impeller 1616. Expandable members may also be referred to hereinas expandable scaffolds or scaffold sections. Expandable scaffold 1602is disposed radially outside of the impellers along the axial length ofthe impellers. Expandable scaffold 1602 can be constructed in a mannerand made from materials similar to many types of expandable structuresthat are known in the medical arts to be able to collapsed and expanded,examples of which are provided herein. Examples of suitable materialsinclude, but are not limited to, polyurethane, polyurethane elastomers,metallic alloys, etc.

Pump portion 1600 also includes blood conduit 1604, which is coupled toand supported by expandable member 1602, has a length L, and extendsaxially between the impellers. Conduit 1604 creates and provides a fluidlumen between the two impellers. When in use, fluid moves through thelumen defined by conduit 1604. The conduits herein may be non-permeable,or they may be semi-permeable, or even porous as long as they stilldefine a lumen. The conduits herein are also flexible, unless otherwiseindicated. The conduits herein extend completely around (i.e., 360degrees) at least a portion of the pump portion. In pump portion 1600,the conduit extends completely around expandable member 1602, but doesnot extend all the way to the proximal end 1602 or distal end 1608 ofexpandable member 1602. The structure of the expandable member createsat least one inlet aperture to allow for inflow “I,” and at least oneoutflow aperture to allow for outflow “0.” Conduit 1604 improvesimpeller pumping dynamics, compared to pump portions without a conduit.As described herein, expandable members or scaffolds may also beconsidered to be a part of the blood conduit generally, which togetherdefine a blood lumen. In these instances the scaffold and materialsupported by the scaffold may be referred to herein as an expandableimpeller housing or housing.

Expandable member 1602 may have a variety of constructions, and madefrom a variety of materials. For example, expandable member 1602 may beformed similar to expandable stents or stent-like devices, or any otherexample provided herein. For example without limitation, expandablemember 1602 could have an open-braided construction, such as a 24-endbraid, although more or fewer braid wires could be used. Exemplarymaterials for the expandable member as well as the struts herein includenitinol, cobalt alloys, and polymers, although other materials could beused. Expandable member 1602 has an expanded configuration, as shown, inwhich the outer dimension (measured orthogonally relative a longitudinalaxis of the working portion) of the expandable member is greater in atleast a region where it is disposed radially outside of the impellersthan in a central region 1622 of the expandable member that extendsaxially between the impeller. Drive mechanism 1612 is co-axial with thelongitudinal axis in this embodiment. In use, the central region can beplaced across a valve, such as an aortic valve. In some embodiments,expandable member 1602 is adapted and constructed to expand to anoutermost dimension of 12-24 F (4.0-8.0 mm) where the impellers areaxially within the expandable member, and to an outermost dimension of10-20 F (3.3-6.7 mm) in central region 1622 between the impellers. Thesmaller central region outer dimension can reduce forces acting on thevalve, which can reduce or minimize damage to the valve. The largerdimensions of the expandable member in the regions of the impellers canhelp stabilize the working portion axially when in use. Expandablemember 1602 has a general dumbbell configuration. Expandable member 1602has an outer configuration that tapers as it transitions from theimpeller regions to central region 1622, and again tapers at the distaland proximal ends of expandable member 1602.

Expandable member 1602 has a proximal end 1620 that is coupled to shaft1610, and a distal end 1608 that is coupled to distal tip 1624. Theimpellers and drive mechanism 1612 rotate within the expandable memberand conduit assembly. Drive mechanism 1612 is axially stabilized withrespect to distal tip 1624, but is free to rotate with respect to tip1624.

In some embodiments, expandable member 1602 can be collapsed by pullingtension from end-to-end on the expandable member. This may includelinear motion (such as, for example without limitation, 5-20 mm oftravel) to axially extend expandable member 1602 to a collapsedconfiguration with collapsed outer dimension(s). Expandable member 1602can also be collapsed by pushing an outer shaft such as a sheath overthe expandable member/conduit assembly, causing the expandable memberand conduit to collapse towards their collapsed delivery configuration.

Impellers 1606 and 1616 are also adapted and constructed such that oneor more blades will stretch or radially compress to a reduced outermostdimension (measured orthogonally to the longitudinal axis of the workingportion). For example without limitation, any of the impellers hereincan include one or more blades made from a plastic formulation withspring characteristics, such as any of the impellers described in U.S.Pat. No. 7,393,181, the disclosure of which is incorporated by referenceherein for all purposes and can be incorporated into embodiments hereinunless this disclosure indicates to the contrary. Alternatively, forexample, one or more collapsible impellers can comprise a superelasticwire frame, with polymer or other material that acts as a webbing acrossthe wire frame, such as those described in U.S. Pat. No. 6,533,716, thedisclosure of which is incorporated by reference herein for allpurposes.

The inflow and/or outflow configurations of working portion 1600 can bemostly axial in nature.

Exemplary sheathing and unsheathing techniques and concepts to collapseand expand medical devices are known, such as, for example, thosedescribed and shown in U.S. Pat. Nos. 7,841,976 or 8,052,749, thedisclosures of which are incorporated by reference herein.

FIG. 2 is a side view illustrating a deployed configuration (shownextracorporally) of a distal portion of an exemplary embodiment of acatheter blood pump. Exemplary blood pump 1100 includes working portion1104 (which as set forth herein may also be referred to herein as a pumpportion) and an elongate portion 1106 extending from working portion1104. Elongate portion 1106 can extend to a more proximal region of thesystem, not shown for clarity, and that can include, for example, amotor. Working portion 1104 includes first expandable scaffold or member1108 and second expandable scaffold or member 1110, axially spaced apartalong a longitudinal axis LA of working portion 1104. First scaffold1108 and second scaffold 1110 (and any other separate scaffolds herein)may also be referenced as part of a common scaffold and referred toherein as scaffold sections. Spaced axially in this context refers tothe entire first expandable member being axially spaced from the entiresecond expandable member along a longitudinal axis LA of working portion1104. A first end 1122 of first expandable member 1108 is axially spacedfrom a first end 1124 of second expandable member 1110.

First and second expandable members 1108 and 1110 generally each includea plurality of elongate segments disposed relative to one another todefine a plurality of apertures 1130, only one of which is labeled inthe second expandable member 1110. The expandable members can have awide variety of configurations and can be constructed in a wide varietyof ways, such as any of the configurations or constructions in, forexample without limitation, U.S. Pat. No. 7,841,976, or the tube in U.S.Pat. No. 6,533,716, which is described as a self-expanding metalendoprosthetic material. For example, without limitation, one or both ofthe expandable members can have a braided construction or can be atleast partially formed by laser cutting a tubular element.

Working portion 1104 also includes blood conduit 1112 that is coupled tofirst expandable member 1108 and to second expandable member 1110, andextends axially in between first expandable member 1108 and secondexpandable member 1110 in the deployed configuration. A central region1113 of conduit 1112 spans an axial distance 1132 where the workingportion is void of first and second expandable members 1108 and 1110.Central region 1113 can be considered to be axially in between theexpandable members. Distal end 1126 of conduit 1112 does not extend asfar distally as a distal end 1125 of second expandable member 1110, andproximal end of conduit 1128 does not extend as far proximally asproximal end 1121 of first expandable member 1108.

When the disclosure herein refers to a blood conduit being coupled to anexpandable scaffold or member, the term coupled in this context does notrequire that the conduit be directly attached to the expandable memberso that conduit physically contacts the expandable member. Even if notdirectly attached, however, the term coupled in this context refers tothe conduit and the expandable member being joined together such that asthe expandable member expands or collapses, the conduit also begins totransition to a different configuration and/or size. Coupled in thiscontext therefore refers to conduits that will move when the expandablemember to which it is coupled transitions between expanded and collapsedconfigurations.

Any of the blood conduits herein can be deformable to some extent. Forexample, conduit 1112 includes elongate member 1120 that can be made ofone or more materials that allow the central region 1113 of conduit todeform to some extent radially inward (towards LA) in response to, forexample and when in use, forces from valve tissue (e.g., leaflets) or areplacement valve as working portion 1104 is deployed towards theconfiguration shown in FIG. 2. The conduit may be stretched tightlybetween the expandable members in some embodiments. The conduit mayalternatively be designed with a looseness that causes a greater degreeof compliance. This can be desirable when the working portion isdisposed across fragile structures such as an aortic valve, which mayallow the valve to compress the conduit in a way that minimizes pointstresses in the valve. In some embodiments, the conduit may include amembrane attached to the proximal and distal expandable members.Exemplary materials that can be used for any conduits herein include,without limitations, polyurethane rubber, silicone rubber, acrylicrubber, expanded polytetrafluoroethylene, polyethylene, polyethyleneterephthalate, including any combination thereof.

Any of the conduits herein can have a thickness of, for example, 0.5-20thousandths of an inch (thou), such as 1-15 thou, or 1.5 to 15 thou, 1.5to 10 thou, or 2 to 10 thou.

Any of the blood conduits herein, or at least a portion of the conduit,can be impermeable to blood. In FIG. 2, working portion 1104 includes alumen that extends from distal end 1126 of conduit 1112 and extends toproximal end 1128 of conduit 1112. The lumen is defined by conduit 1112in central region 1113, but can be thought of being defined by both theconduit and portions of the expandable members in regions axiallyadjacent to central region 1113. In this embodiment, however, it is theconduit material that causes the lumen to exist and prevents blood frompassing through the conduit.

Any of the conduits herein that are secured to one or more expandablemembers can be, unless indicated to the contrary, secured so that theconduit is disposed radially outside of one or more expandable members,radially inside of one or more expandable members, or both, and theexpandable member can be impregnated with the conduit material.

The proximal and distal expandable scaffolds or members help maintainthe blood conduit in an open configuration to create the lumen, whileeach also creates a working environment for an impeller, describedbelow. Each of the expandable scaffolds, when in the deployedconfiguration, is maintained in a spaced relationship relative to arespective impeller, which allows the impeller to rotate within theexpandable member without contacting the expandable member. Workingportion 1104 includes first impeller 1116 and second impeller 1118, withfirst impeller 1116 disposed radially within first expandable member1108 and second impeller 1118 disposed radially within second expandablemember 1110. In this embodiment, the two impellers even though they aredistinct and separate impellers, are in operable communication with acommon drive mechanism (e.g., drive cable 1117), such that when thedrive mechanism is activated the two impellers rotate together. In thisdeployed configuration, impellers 1116 and 1118 are axially spaced apartalong longitudinal axis LA, just as are the expandable members 1108 and1110 are axially spaced apart.

Impellers 1116 and 1118 are also axially within the ends of expandablemembers 1108 and 1110, respectively (in addition to being radiallywithin expandable members 1108 and 1110). The impellers herein can beconsidered to be axially within an expandable member even if theexpandable member includes struts extending from a central region of theexpandable member towards a longitudinal axis of the working portion(e.g., tapering struts in a side view). In FIG. 2, second expandablemember 1110 extends from first end 1124 (proximal end) to second end1125 (distal end).

In FIG. 2, a distal portion of impeller 1118 extends distally beyonddistal end 1126 of conduit 1112, and a proximal portion of impeller 1116extends proximally beyond proximal end 1128 of conduit 1112. In thisfigure, portions of each impeller are axially within the conduit in thisdeployed configuration.

In the exemplary embodiment shown in FIG. 2, impellers 1116 and 1118 arein operable communication with a common drive mechanism 1117, and inthis embodiment, the impellers are each coupled to drive mechanism 1117,which extends through shaft 1119 and working portion 1104. Drivemechanism 1117 can be, for example, an elongate drive cable, which whenrotated causes the impellers to rotate. In this example, as shown, drivemechanism 1117 extends to and is axially fixed relative to distal tip1114, although it is adapted to rotate relative to distal tip 1114 whenactuated. Thus, in this embodiment, the impellers and drive mechanism1117 rotate together when the drive mechanism is rotated. Any number ofknown mechanisms can be used to rotate drive mechanism, such as with amotor (e.g., an external motor).

The expandable members and the conduit are not in rotational operablecommunication with the impellers and the drive mechanism. In thisembodiment, proximal end 1121 of proximal expandable member 1108 iscoupled to shaft 1119, which may be a shaft of elongate portion 1106(e.g., an outer catheter shaft). Distal end 1122 of proximal expandablemember 1108 is coupled to central tubular member 1133, through whichdrive mechanism 1117 extends. Central tubular member 1133 extendsdistally from proximal expandable member 1108 within conduit 1112 and isalso coupled to proximal end 1124 of distal expandable member 1110.Drive mechanism 1117 thus rotates within and relative to central tubularmember 1133. Central tubular member 1133 extends axially from proximalexpandable member 1108 to distal expandable member 1110. Distal end 1125of distal expandable member 1110 is coupled to distal tip 1114, asshown. Drive mechanism 1117 is adapted to rotate relative to tip 1114,but is axially fixed relative to tip 1114.

Working portion 1104 is adapted and configured to be collapsed to asmaller profile than its deployed configuration (which is shown in FIG.2). This allows it to be delivered using a lower profile delivery device(smaller French size) than would be required if none of working portion1104 was collapsible. Even if not specifically stated herein, any of theexpandable members and impellers may be adapted and configured to becollapsible to some extent to a smaller delivery configuration.

The working portions herein can be collapsed to a collapsed deliveryconfiguration using conventional techniques, such as with an outersheath that is movable relative to the working portion (e.g., by axiallymoving one or both of the sheath and working portion). For examplewithout limitation, any of the systems, devices, or methods shown in thefollowing references may be used to facilitate the collapse of a workingportions herein: U.S. Pat. Nos. 7,841,976 or 8,052,749, the disclosuresof which are incorporated by reference herein for all purposes.

FIGS. 3A-3D show an exemplary pump portion that is similar in some waysto the pump portion shown in FIG. 2. Pump portion 340 is similar to pumpportion 1104 in that in includes two expandable members axially spacedfrom one another when the pump portion is expanded, and a conduitextending between the two expandable members. FIG. 3A is a perspectiveview, FIG. 3B is a side sectional view, and FIGS. 3C and 3D are close-upside sectional views of sections of the view in FIG. 3B.

Pump portion 340 includes proximal impeller 341 and distal impeller 342,which are coupled to and in operational communication with a drivecable, which defines therein a lumen. The lumen can be sized toaccommodate a guidewire, which can be used for delivery of the workingportion to the desired location. The drive cable, in this embodiment,includes first section 362 (e.g., wound material), second section 348(e.g., tubular member) to which proximal impeller 341 is coupled, thirdsection 360 (e.g., wound material), and fourth section 365 (e.g.,tubular material) to which distal impeller 342 is coupled. The drivecable sections all have the same inner diameter, so that lumen has aconstant inner diameter. The drive cable sections can be secured to eachother using known attachment techniques. A distal end of fourth section365 extends to a distal region of the working portion, allowing theworking portion to be, for example, advanced over a guidewire forpositioning the working portion. In this embodiment the second andfourth sections can be stiffer than first and third sections. Forexample, second and fourth can be tubular and first and third sectionscan be wound material to impart less stiffness.

Pump portion 340 includes proximal expandable scaffold 343 and distalexpandable scaffold 344, each of which extends radially outside of oneof the impellers. The expandable scaffolds have distal and proximal endsthat also extend axially beyond distal and proximal ends of theimpellers, which can be seen in FIGS. 3B-3D. Coupled to the twoexpandable scaffolds is blood conduit 356, which has a proximal end 353and a distal end 352. The two expandable scaffolds each include aplurality of proximal struts and a plurality of distal struts. Theproximal struts in proximal expandable scaffold 343 extend to and aresecured to shaft section 345, which is coupled to bearing 361, throughwhich the drive cable extends and is configured and sized to rotate. Thedistal struts of proximal expandable scaffold 343 extend to and aresecured to a proximal region (to a proximal end in this case) of centraltubular member 346, which is disposed axially in between the expandablemembers. The proximal end of central tubular member 346 is coupled tobearing 349, as shown in FIG. 3C, through which the drive cable extendsand rotates. The proximal struts extend axially from distal expandablescaffold 344 to and are secured to a distal region (to a distal end inthis case) of central tubular member 346. Bearing 350 is also coupled tothe distal region of central tubular member 346, as is shown in FIG. 3D.The drive cable extends through and rotates relative to bearing 350.Distal struts extend from the distal expandable scaffold extend to andare secured to shaft section 347 (see FIG. 3A), which can be consideredpart of the distal tip. Shaft section 347 is coupled to bearing 351 (seeFIG. 3D), through which the drive cable extends and rotates relative to.The distal tip also includes bearing 366 (see FIG. 3D), which can be athrust bearing. Working portion 340 can be similar to or the same insome aspects to working portion 1104, even if not explicitly included inthe description. In this embodiment, conduit 356 extends at least as faras ends of the impeller, unlike in working portion 1104. Eitherembodiment can be modified so that the conduit extends to a position asset forth in the other embodiment. In some embodiments, section 360 canbe a tubular section instead of wound.

In alternative embodiments, at least a portion of any of the impellersherein may extend outside of the fluid lumen. For example, only aportion of an impeller may extend beyond an end of the fluid lumen ineither the proximal or distal direction. In some embodiments, a portionof an impeller that extends outside of the fluid lumen is a proximalportion of the impeller, and includes a proximal end (e.g., see theproximal impeller in FIG. 2). In some embodiments, the portion of theimpeller that extends outside of the fluid lumen is a distal portion ofthe impeller, and includes a distal end (e.g., see the distal impellerin FIG. 2). When the disclosure herein refers to impellers that extendoutside of the fluid lumen (or beyond an end), it is meant to refer torelative axial positions of the components, which can be most easilyseen in side views or top views, such as in FIG. 2.

A second impeller at another end of the fluid lumen may not, however,extend beyond the fluid lumen. For example, an illustrative alternativedesign can include a proximal impeller that extends proximally beyond aproximal end of the fluid lumen (like the proximal impeller in FIG. 2),and the fluid lumen does not extend distally beyond a distal end of adistal impeller (like in FIG. 3B). Alternatively, a distal end of adistal impeller can extend distally beyond a distal end of the fluidlumen, but a proximal end of a proximal impeller does not extendproximally beyond a proximal end of the fluid lumen. In any of the pumpportions herein, none of the impellers may extend beyond ends of thefluid lumen.

While specific exemplary locations may be shown herein, the fluid pumpsmay be able to be used in a variety of locations within a body. Someexemplary locations for placement include placement in the vicinity ofan aortic valve or pulmonary valve, such as spanning the valve andpositioned on one or both sides of the valve, and in the case of anaortic valve, optionally including a portion positioned in the ascendingaorta. In some other embodiments, for example, the pumps may be, in use,positioned further downstream, such as being disposed in a descendingaorta.

FIG. 4 illustrates an exemplary placement of pump portion 1104 fromcatheter blood pump 1000 from FIG. 2. Once difference shown in FIG. 4 isthat the conduit extends at least as far as the ends of the impellers,like in FIGS. 3A-3D. FIG. 4 shows pump portion 1104 in a deployedconfiguration, positioned in place across an aortic valve. Pump portion1104 can be delivered as shown via, for example without limitation,femoral artery access (a known access procedure). While not shown forclarity, system 1000 can also include an outer sheath or shaft in whichworking portion 1104 is disposed during delivery to a location near anaortic valve. The sheath or shaft can be moved proximally (towards theascending aorta “AA” and away from left ventricle “LV”) to allow fordeployment and expansion of working portion 1104. For example, thesheath can be withdrawn to allow for expansion of second expandablescaffold 1110, with continued proximal movement allowing firstexpandable scaffold 1108 to expand.

In this embodiment, second expandable scaffold 1110 has been expandedand positioned in a deployed configuration such that distal end 1125 isin the left ventricle “LV,” and distal to aortic valve leaflets “VL,” aswell as distal to the annulus. Proximal end 1124 has also beenpositioned distal to leaflets VL, but in some methods proximal end 1124may extend slightly axially within the leaflets VL. This embodiment isan example of a method in which at least half of the second expandablemember 1110 is within the left ventricle, as measured along its length(measured along the longitudinal axis). And as shown, this is also anexample of a method in which the entire second expandable member 1110 iswithin the left ventricle. This is also an example of a method in whichat least half of second impeller 1118 is positioned within the leftventricle, and also an embodiment in which the entire second impeller1118 is positioned within the left ventricle.

Continued retraction of an outer shaft or sheath (and/or distal movementof working end 1104 relative to an outer sheath or shaft) continues torelease conduit 1112, until central region 1113 is released anddeployed. The expansion of expandable scaffolds 1108 and 1110 causesblood conduit 1112 to assume a more open configuration, as shown in FIG.4. Thus, while in this embodiment conduit 1112 does not have the sameself-expanding properties as the expandable scaffolds, the conduit willassume a deployed, more open configuration when the working end isdeployed. At least a portion of central region 1113 of conduit 1112 ispositioned at an aortic valve coaptation region and engages leaflets. InFIG. 3, there is a short length of central region 1113 that extendsdistally beyond the leaflets VL, but at least some portion of centralregion 1113 is axially within the leaflets.

Continued retraction of an outer shaft or sheath (and/or distal movementof working end 1104 relative to an outer sheath or shaft) deploys firstexpandable member 1108. In this embodiment, first expandable scaffold1108 has been expanded and positioned (as shown) in a deployedconfiguration such that proximal end 1121 is in the ascending aorta AA,and proximal to leaflets “VL.” Distal end 1122 has also been positionedproximal to leaflets VL, but in some methods distal end 1122 may extendslightly axially within the leaflets VL. This embodiment is an exampleof a method in which at least half of first expandable member 1110 iswithin the ascending aorta, as measured along its length (measured alongthe longitudinal axis). And as shown, this is also an example of amethod in which the entire first expandable member 1110 is within theAA. This is also an example of a method in which at least half of firstimpeller 1116 is positioned within the AA, and also an embodiment inwhich the entire first impeller 1116 is positioned within the AA.

At any time during or after deployment of pump portion 1104, theposition of the pump portion can be assessed in any way, such as underfluoroscopy. The position of the pump portion can be adjusted at anytime during or after deployment. For example, after second expandablescaffold 1110 is released but before first expandable member 1108 isreleased, pump portion 1104 can be moved axially (distally orproximally) to reposition the pump portion. Additionally, for example,the pump portion can be repositioned after the entire working portionhas been released from a sheath to a desired final position.

It is understood that the positions of the components (relative to theanatomy) shown in FIG. 4 are considered exemplary final positions forthe different components of working portion 1104, even if there wasrepositioning that occurred after initial deployment.

The one or more expandable members herein can be configured to be, andcan be expanded in a variety of ways, such as via self-expansion,mechanical actuation (e.g., one or more axially directed forces on theexpandable member, expanded with a separate balloon positioned radiallywithin the expandable member and inflated to push radially outward onthe expandable member), or a combination thereof.

Expansion as used herein refers generally to reconfiguration to a largerprofile with a larger radially outermost dimension (relative to thelongitudinal axis), regardless of the specific manner in which the oneor more components are expanded. For example, a stent that self-expandsand/or is subject to a radially outward force can “expand” as that termis used herein. A device that unfurls or unrolls can also assume alarger profile, and can be considered to expand as that term is usedherein.

The impellers can similarly be adapted and configured to be, and can beexpanded in a variety of ways depending on their construction. Forexamples, one or more impellers can, upon release from a sheath,automatically revert to or towards a different larger profileconfiguration due to the material(s) and/or construction of the impellerdesign (see, for example, U.S. Pat. No. 6,533,716, or U.S. Pat. No.7,393,181, both of which are incorporated by reference herein for allpurposes). Retraction of an outer restraint can thus, in someembodiments, allow both the expandable member and the impeller to revertnaturally to a larger profile, deployed configuration without anyfurther actuation.

As shown in the example in FIG. 4, the working portion includes firstand second impellers that are spaced on either side of an aortic valve,each disposed within a separate expandable member. This is in contrastto some designs in which a working portion includes a single elongateexpandable member. Rather than a single generally tubular expandablemember extending all the way across the valve, working end 1104 includesa conduit 1112 extending between expandable members 1108 and 1110. Theconduit is more flexible and deformable than the expandable baskets,which can allow for more deformation of the working portion at thelocation of the leaflets than would occur if an expandable memberspanned the aortic valve leaflets. This can cause less damage to theleaflets after the working portion has been deployed in the subject.

Additionally, forces on a central region of a single expandable memberfrom the leaflets might translate axially to other regions of theexpandable member, perhaps causing undesired deformation of theexpandable member at the locations of the one or more impellers. Thismay cause the outer expandable member to contact the impeller,undesirably interfering with the rotation of the impeller. Designs thatinclude separate expandable members around each impeller, particularlywhere each expandable member and each impeller are supported at bothends (i.e., distal and proximal), result in a high level of precision inlocating the impeller relative to the expandable member. Two separateexpandable members may be able to more reliably retain their deployedconfigurations compared with a single expandable member.

As described herein above, it may be desirable to be able to reconfigurethe working portion so that it can be delivered within a 9F sheath andstill obtain high enough flow rates when in use, which is not possiblewith some products currently in development and/or testing. For example,some products are too large to be able to be reconfigured to a smallenough delivery profile, while some smaller designs may not be able toachieve the desired high flow rates. An exemplary advantage of theexamples in FIGS. 1, 2, 3A-3D and 4 is that, for example, the first andsecond impellers can work together to achieve the desired flow rates,and by having two axially spaced impellers, the overall working portioncan be reconfigured to a smaller delivery profile than designs in whicha single impeller is used to achieved the desired flow rates. Theseembodiments thus use a plurality of smaller, reconfigurable impellersthat are axially spaced to achieve both the desired smaller deliveryprofile as well as to achieve the desired high flow rates.

The embodiment herein can thus achieve a smaller delivery profile whilemaintaining sufficiently high flow rates, while creating a moredeformable and flexible central region of the working portion, theexemplary benefits of which are described above (e.g., interfacing withdelicate valve leaflets).

FIG. 5 illustrates a working portion that is similar to the workingportion shown in FIG. 1. Working portion 265 includes proximal impeller266, distal impeller 267, both of which are coupled to drive shaft 278,which extends into distal bearing housing 272. There is a similarproximal bearing housing at the proximal end of the working portion.Working portion also includes expandable scaffold or member, referred to270 generally, and blood conduit 268 that is secured to the expandablemember and extends almost the entire length of expandable member.Expandable member 270 includes distal struts 271 that extend to and aresecured to strut support 273, which is secured to distal tip 273.Expandable member 270 also includes proximal struts there are secured toa proximal strut support. All features similar to that shown in FIG. 1are incorporated by reference for all purposes into this embodiment evenif not explicitly stated. Expandable member 265 also includes helicaltension member 269 that is disposed along the periphery of theexpandable member, and has a helical configuration when the expandablemember is in the expanded configuration as shown. The helical tensionmember 269 is disposed and adapted to induce rotation wrap uponcollapse. Working portion 265 can be collapsed from the shown expandedconfiguration while simultaneously rotating one or both impellers at arelatively slow speed to facilitate curled collapse of the impellers dueto interaction with the expandable member. Helical tension member 269(or a helical arrangement of expandable member cells) will act as acollective tension member and is configured so that when the expandablebasket is pulled in tension along its length to collapse (such as bystretching to a much greater length, such as approximately doubling inlength) tension member 269 is pulled into a straighter alignment, whichcauses rotation/twisting of the desired segment(s) of the expandablemember during collapse, which causes the impeller blades to wrapradially inward as the expandable member and blades collapse. Anexemplary configuration of such a tension member would have acurvilinear configuration when in helical form that is approximatelyequal to the maximum length of the expandable member when collapsed. Inalternative embodiments, only the portion(s) of the expandable memberthat encloses a collapsible impeller is caused to rotate upon collapse.

There are alternative ways to construct the working portion to causerotation of the expandable member upon collapse by elongation (and thuscause wrapping and collapse of the impeller blades). Any expandablemember can be constructed with this feature, even in dual-impellerdesigns. For example, with an expandable member that includes aplurality of “cells,” as that term is commonly known (e.g., a laser cutelongate member), the expandable member may have a plurality ofparticular cells that together define a particular configuration such asa helical configuration, wherein the cells that define the configurationhave different physical characteristics than other cells in theexpandable member. In some embodiments the expandable member can have abraided construction, and the twist region may constitute the entiregroup of wires, or a significant portion (e.g., more than half), of thebraided wires. Such a twisted braid construction may be accomplished,for example, during the braiding process, such as by twisting themandrel that the wires are braided onto as the mandrel is pulled along,especially along the length of the largest-diameter portion of thebraided structure. The construction could also be accomplished during asecond operation of the construction process, such as mechanicallytwisting a braided structure prior to heat-setting the wound profileover a shaped mandrel.

Any of the blood conduits herein act to, are configured to, and are madeof material(s) that create a fluid lumen therein between a first end(e.g., distal end) and a second end (e.g., proximal end). Fluid flowsinto the inflow region, through the fluid lumen, and then out of anoutflow region. Flow into the inflow region may be labeled herein as“I,” and flow out at the outflow region may be labeled “0.” Any of theconduits herein can be impermeable. Any of the conduits herein canalternatively be semipermeable. Any of the conduits herein may also beporous, but will still define a fluid lumen therethrough. In someembodiments the conduit is a membrane, or other relatively thin layeredmember. Any of the conduits herein, unless indicated to the contrary,can be secured to an expandable member such that the conduit, where isit secured, can be radially inside and/or outside of the expandablemember. For example, a conduit may extend radially within the expandablemember so that inner surface of the conduit is radially within theexpandable member where it is secured to the expandable member.

Any of the expandable scaffolds or member(s) herein may be constructedof a variety of materials and in a variety of ways. For example, theexpandable member may have a braided construction, or it can be formedby laser machining. The material can be deformable, such as nitinol. Theexpandable member can be self-expanding or can be adapted to be at leastpartially actively expanded.

In some embodiments, the expandable scaffold or member is adapted toself-expand when released from within a containing tubular member suchas a delivery catheter, a guide catheter or an access sheath. In somealternative embodiments, the expandable member is adapted to expand byactive expansion, such as action of a pull-rod that moves at least oneof the distal end and the proximal end of the expandable member towardeach other. In alternative embodiments, the deployed configuration canbe influenced by the configuration of one or more expandable structures.In some embodiments, the one or more expandable members can deployed, atleast in part, through the influence of blood flowing through theconduit. Any combination of the above mechanisms of expansion may beused.

The blood pumps and fluid movement devices, system and methods hereincan be used and positioned in a variety of locations within a body.While specific examples may be provided herein, it is understood thatthat the working portions can be positioned in different regions of abody than those specifically described herein.

In any of the embodiments herein in which the catheter blood pumpincludes a plurality of impellers, the device can be adapted such thatthe impellers rotate at different speeds. FIG. 6A illustrates a medicaldevice that includes gearset 1340 coupled to both inner drive member1338 and outer drive member 1336, which are in operable communicationwith distal impeller 1334 and proximal impeller 1332, respectively. Thedevice also includes motor 1342, which drives the rotation of innerdrive member 1338. Inner drive member 1338 extends through outer drivemember 1336. Activation of the motor 1332 causes the two impellers torotate at different speeds due to an underdrive or overdrive ratio.Gearset 1340 can be adapted to drive either the proximal or distalimpeller faster than the other. Any of the devices herein can includeany of the gearsets herein to drive the impellers at different speeds.

FIG. 6B illustrates a portion of an alternative embodiment of a dualimpeller device (1350) that is also adapted such that the differentimpellers rotate at different speeds. Gearset 1356 is coupled to bothinner drive member 1351 and outer drive member 1353, which are coupledto distal impeller 1352 and proximal impeller 1354, respectively. Thedevice also includes a motor like in FIG. 6A. FIGS. 6A and 6B illustratehow a gearset can be adapted to drive the proximal impeller slower orfaster than the distal impeller.

FIG. 7 illustrates an exemplary alternative embodiment of fluid pump1370 that can rotate first and second impellers at different speeds.First motor 1382 drives cable 1376, which is coupled to distal impeller1372, while second motor 1384 drives outer drive member 1378 (viagearset 1380), which is coupled to proximal impeller 1374. Drive cable1376 extends through outer drive member 1378. The motors can beindividually controlled and operated, and thus the speeds of the twoimpellers can be controlled separately. This system setup can be usedwith any system herein that includes a plurality of impellers.

In some embodiments, a common drive mechanism (e.g., cable and/or shaft)can drive the rotation of two (or more) impellers, but the blade pitchof the two impellers (angle of rotational curvature) can be different,with the distal or proximal impeller having a steeper or more gradualangle than the other impeller. This can produce a similar effect tohaving a gearset. FIG. 6C shows a portion of a medical device (1360)that includes common drive cable 1366 coupled to proximal impeller 1364and distal impeller 1362, and to a motor not shown. The proximalimpellers herein can have a greater or less pitch than the distalimpellers herein. Any of the working portions (or distal portions)herein with a plurality of impellers can be modified to include firstand second impellers with different pitches.

In any of the embodiments herein, the pump portion may have a compliantor semi-compliant (referred to generally together as “compliant”)exterior structure. In various embodiments, the compliant portion ispliable. In various embodiments, the compliant portion deforms onlypartially under pressure. For example, the central portion of the pumpmay be formed of a compliant exterior structure such that it deforms inresponse to forces of the valve. In this manner the exterior forces ofthe pump on the valve leaflets are reduced. This can help prevent damageto the valve at the location where it spans the valve.

FIG. 8 illustrates an exemplary embodiment of a pump portion thatincludes first, second and third axially spaced impellers 152, each ofwhich is disposed within an expandable member 154. Conduit 155 canextend along the length of the pump portion, as in described in variousembodiments herein, which can help create and define the fluid lumen. Inalternative embodiments, however, the first, second, and third impellersmay be disposed within a single expandable member, similar to that shownin FIG. 1. In FIG. 8, a fluid lumen extends from a distal end to aproximal end, features of which are described elsewhere herein. Theembodiment in FIG. 8 can include any other suitable feature, includingmethods of use, described herein.

The embodiment in FIG. 8 is also an example of an outer housing havingat least one bend formed therein between a proximal impeller distal endand a distal impeller proximal end, such that a distal region of thehousing distal to the bend is not axially aligned with a proximal regionof the housing proximal to the bend along an axis. In this embodimentthere are two bends 150 and 151 formed in the housing, each one betweentwo adjacent impellers.

In a method of use, a bend formed in a housing can be positioned to spana valve, such as the aortic valve shown in FIG. 8. In this method ofplacement, a central impeller and distal-most impeller are positioned inthe left ventricle, and a proximal-most impeller is positioned in theascending aorta. Bend 151 is positioned just downstream to the aorticvalve.

A bend such as bend 150 or 151 can be incorporated into any of theembodiments or designs herein. The bend may be a preformed angle or maybe adjustable in situ.

In any of the embodiments herein, unless indicated to the contrary, theouter housing can have a substantially uniform diameter along itslength.

In FIG. 8, the pump is positioned via the axillary artery, which is anexemplary method of accessing the aortic valve, and which allows thepatient to walk and be active with less interruption. Any of the devicesherein can be positioned via the axillary artery. It will be appreciatedfrom the description herein, however, that the pump may be introducedand tracked into position in various manners including a femoralapproach over the aortic arch.

One aspect of the disclosure is a catheter blood pump that includes adistal impeller axially spaced from a proximal impeller. Distal andproximal impellers may be axially spaced from each other. For example,the distal and proximal impellers may be connected solely by theirindividual attachment to a common drive mechanism. This is differentfrom a single impeller having multiple blade rows or sections. A distalimpeller as that phrase is used herein does not necessarily mean adistal-most impeller of the pump, but can refer generally to an impellerthat is positioned further distally than a proximal impeller, even ifthere is an additional impeller than is disposed further distally thanthe distal impeller. Similarly, a proximal impeller as that phrase isused herein does not necessarily mean a proximal-most impeller of thepump, but can refer generally to an impeller that is positioned furtherproximally than a proximal impeller, even if there is an additionalimpeller than is disposed further proximally than the proximal impeller.Axial spacing (or some derivative thereof) refers to spacing along thelength of a pump portion, such as along a longitudinal axis of the pumpportion, even if there is a bend in the pump portion. In variousembodiments, each of the proximal and distal impellers are positionedwithin respective housings and configured to maintain a precise,consistent tip gap, and the span between the impellers has a relativelymore flexible (or completely flexible) fluid lumen. For example, each ofthe impellers may be positioned within a respective housing havingrelatively rigid outer wall to resist radial collapse. The sectionsbetween the impellers may be relatively rigid, in some embodiments thesection is held open primarily by the fluid pressure within.

Although not required for the embodiments therein, there may beadvantages to having a minimum axial spacing between a proximal impellerand a distal impeller. For example, a pump portion may be delivered to atarget location through parts of the anatomy that have relatively tightbends, such as, for example, an aorta, and down into the aortic valve.For example, a pump portion may be delivered through a femoral arteryaccess and to an aortic valve. I t can be advantageous to have a systemthat is easier to bend so that it is easier to deliver the systemthrough the bend(s) in the anatomy. Some designs where multipleimpellers are quite close to each other may make the system, along thelength that spans the multiple impellers, relatively stiff along thatentire length that spans the multiple impellers. Spacing the impellersapart axially, and optionally providing a relatively flexible region inbetween the impellers, can create a part of the system that is moreflexible, is easier to bend, and can be advanced through the bends moreeasily and more safely. An additional exemplary advantage is that theaxial spacing can allow for a relatively more compliant region betweenthe impellers, which can be positioned at, for example, the location ofa valve (e.g., an aortic valve). Furthermore, there are other potentialadvantages and functional differences between the various embodimentsherein and typical multistage pumps. A typical multistage pump includesrows of blades (sometimes referred to as impellers) in close functionalspacing such that the rows of blades act together as a synchronizedstage. One will appreciate that the flow may separate as it passesthrough the distal impeller. In various embodiments as described herein,distal and proximal impellers can be spaced sufficiently apart such thatthe flow separation from the distal impeller is substantially reduced(i.e., increased flow reattachment) and the localized turbulent flow isdissipated before the flow enters the proximal impeller.

In any of the embodiments or in any part of the description herein thatinclude a distal impeller and a proximal impeller, the axial spacingbetween a distal end of the proximal impeller and a proximal end of thedistal impeller can be from 1.5 cm to 25 cm (inclusive) along alongitudinal axis of the pump portion, or along a longitudinal axis of ahousing portion that includes a fluid lumen. The distance may bemeasured when the pump portion, including any impellers, is in anexpanded configuration. This exemplary range can provide the exemplaryflexibility benefits described herein as the pump portion is deliveredthrough curved portions of the anatomy, such as, for example, an aorticvalve via an aorta. FIG. 9 (shown outside a patient in an expandedconfiguration) illustrates length Lc, which illustrates an axial spacingbetween impellers, and in some embodiments may be from 1.5 cm to 25 cmas set forth herein. In embodiments in which there may be more than twoimpellers, any two adjacent impellers (i.e., impellers that do not haveany other rotating impeller in between them) may be spaced axially byany of the axial spacing distances described herein.

While some embodiments include a proximal impeller distal end that isaxially spaced 1.5 cm to 25 cm from a distal impeller proximal end alongan axis, the disclosure herein also includes any axial spacings that aresubranges within that general range of 1.5 cm to 25 cm. That is, thedisclosure includes all ranges that have any lower limit from 1.5 andabove in that range, and all subranges that have any upper limit from 25cm and below. The examples below provide exemplary subranges. In someembodiments, a proximal impeller distal end is axially spaced 1.5 cm to20 cm from a distal impeller proximal end along an axis, 1.5 cm to 15cm, 1.5 cm to 10 cm, 1.5 cm to 7.5 cm, 1.5 cm to 6 cm, 1.5 cm to 4.5 cm,1.5 cm to 3 cm. In some embodiments the axial spacing is 2 cm to 20 cm,2 cm to 15 cm, 2 cm to 12 cm, 2 cm to 10 cm, 2 cm to 7.5 cm, 2 cm to 6cm, 2 cm to 4.5 cm, 2 cm to 3 cm. In some embodiments the axial spacingis 2.5 cm to 15 cm, 2.5 cm to 12.5 cm, 2.5 cm to 10 cm, 2.5 cm to 7.5cm, or 2.5 cm to 5 cm (e.g., 3 cm). In some embodiments the axialspacing is 3 cm to 20 cm, 3 cm to 15 cm, 3 cm to 10 cm, 3 cm to 7.5 cm,3 cm to 6 cm, or 3 cm to 4.5 cm. In some embodiments the axial spacingis 4 cm to 20 cm, 4 cm to 15 cm, 4 cm to 10 cm, 4 cm to 7.5 cm, 4 cm to6 cm, or 4 cm to 4.5 cm. In some embodiments the axial spacing is 5 cmto 20 cm, 5 cm to 15 cm, 5 cm to 10 cm, 5 cm to 7.5 cm, or 5 cm to 6 cm.In some embodiments the axial spacing is 6 cm to 20 cm, 6 cm to 15 cm, 6cm to 10 cm, or 6 cm to 7.5 cm. In some embodiments the axial spacing is7 cm to 20 cm, 7 cm to 15 cm, or 7 cm to 10 cm. In some embodiments theaxial spacing is 8 cm to 20 cm, 8 cm to 15 cm, or 8 cm to 10 cm. In someembodiments the axial spacing is 9 cm to 20 cm, 9 cm to 15 cm, or 9 cmto 10 cm. In various embodiments, the fluid lumen between the impellersis relatively unsupported.

In any of the embodiments herein the one or more impellers may have alength, as measured axially between an impeller distal end and animpeller proximal end (shown as “L_(SD)” and “L_(SP)”, respectively, inFIG. 9), from 0.5 cm to 10 cm, or any subrange thereof. The examplesbelow provide exemplary subranges. In some embodiments the impelleraxial length is from 0.5 cm to 7.5 cm, from 0.5 cm to 5 cm, from 0.5 cmto 4 cm, from 0.5 cm to 3 cm, from 0.5 cm to 2, or from 0.5 cm to 1.5cm. In some embodiments the impeller axial length is from 0.8 cm to 7.5cm, from 0.8 cm to 5 cm, from 0.8 cm to 4 cm, from 0.8 cm to 3 cm, from0.8 cm to 2 cm, or from 0.8 cm to 1.5 cm. In some embodiments theimpeller axial length is from 1 cm to 7.5 cm, from 1 cm to 5 cm, from 1cm to 4 cm, from 1 cm to 3 cm, from 1 cm to 2 cm, or from 1 cm to 1.5cm. In some embodiments the impeller axial length is from 1.2 cm to 7.5cm, from 1.2 cm to 5 cm, from 1.2 cm to 4 cm, from 1.2 cm to 3 cm, from1.2 to 2 cm, or from 1.2 cm to 1.5 cm. In some embodiments the impelleraxial length is from 1.5 cm to 7.5 cm, from 1.5 cm to 5 cm, from 1.5 cmto 4 cm, from 1.5 cm to 3 cm, or from 1.5 cm to 2 cm. In someembodiments the impeller axial length is from 2 cm to 7.5 cm, from 2 cmto 5 cm, from 2 cm to 4 cm, or from 2 cm to 3 cm. In some embodimentsthe impeller axial length is from 3 cm to 7.5 cm, from 3 cm to 5 cm, orfrom 3 cm to 4 cm. In some embodiments the impeller axial length is from4 cm to 7.5 cm, or from 4 cm to 5 cm.

In any of the embodiments herein the fluid lumen can have a length froma distal end to a proximal end, shown as length Lp in FIG. 9. In someembodiments the fluid lumen length Lp is from 4 cm to 40 cm, or anysubrange therein. For example, in some embodiments the length Lp can befrom 4 cm to 30 cm, from 4 cm to 20 cm, from 4 cm to 18 cm, from 4 cm to16 cm, from 4 cm to 14 cm, from 4 cm to 12 cm, from 4 cm to 10 cm, from4 cm to 8 cm, from 4 cm to 6 cm.

In any of the embodiments herein the housing can have a deployeddiameter, at least the location of an impeller (and optionally at alocation between impellers), shown as dimension Dp in FIG. 9. In someembodiments Dp can be from 0.3 cm to 1.5 cm, or any subrange therein.For example, Dp may be from 0.4 cm to 1.4 cm, from 0.4 cm to 1.2 cm,from 0.4 cm to 1.0 cm, from 0.4 cm to 0.8 cm, or from 0.4 cm to 0.6 cm.In some embodiments, Dp may be from 0.5 cm to 1.4 cm, from 0.5 cm to 1.2cm, from 0.5 cm to 1.0 cm, from 0.5 cm to 0.8 cm, or from 0.5 cm to 0.6cm. In some embodiments Dp may be from 0.6 cm to 1.4 cm, from 0.6 cm to1.2 cm, from 0.6 cm to 1.0 cm, or from 0.6 cm to 0.8 cm. In someembodiments Dp may be from 0.7 cm to 1.4 cm, from 0.7 cm to 1.2 cm, from0.7 cm to 1.0 cm, or from 0.7 cm to 0.8 cm.

In any of the embodiments herein an impeller can have a deployeddiameter, shown as dimension Di in FIG. 9. In some embodiments Di can befrom 1 mm-30 mm, or any subrange therein. For example, in someembodiments Di may be from 1 mm-15 mm, from 2 mm-12 mm, from 2.5 mm-10mm, or 3 mm-8 mm.

In any of the embodiments herein, a tip gap exists between an impellerouter diameter and a fluid lumen inner diameter. In some embodiments thetip gap can be from 0.01 mm-1 mm, such as 0.05 mm to 0.8 mm, or such as0.1 mm-0.5 mm.

In any of the embodiments herein that includes multiple impellers, theaxial spacing between impellers (along the length of the pump portion,even if there is a bend in the pump portion) can be from 2 mm to 100 mm,or any combination of upper and lower limits inclusive of 5 and 100 mm(e.g., from 10 mm-80 mm, from 15 mm-70 mm, from 20 mm-50 mm, 2 mm-45 mm,etc.).

Any of the pump portions herein that include a plurality of impellersmay also include more than two impellers, such as three, four, or fiveimpellers (for example).

FIG. 10 illustrates an expandable scaffold 250 that may be one of atleast two expandable scaffolds of a pump portion, such as the expandablescaffolds in FIGS. 3A-3D, wherein each expandable scaffold at leastpartially surrounds an impeller. The scaffold design in FIG. 10 hasproximal struts 251 (only one labeled) extending axially therefrom.Having a separate expandable scaffold 250 for each impeller provides forthe ability to have different geometries for any of the individualimpellers. Additionally, this design reduces the amount of scaffoldmaterial (e.g., Nitinol) over the length of the expandable bloodconduit, which may offer increased tracking when sheathed. A potentialchallenge with these designs may include creating a continuous membranebetween the expandable scaffolds in the absence of an axially extendingscaffolding material (see FIG. 3A). Any other aspect of the expandablescaffolds or members herein, such as those described in FIGS. 3A-3D, maybe incorporated by reference into this exemplary design. Struts 251 maybe disposed at a pump inflow or outflow. Struts 251 may be proximalstruts or they may be distal struts.

FIG. 11 show an exemplary scaffold along an length of the blood conduit.Central region “CR” may be axially between proximal and distalimpellers. Central region “CR” flexibility is increased relative toscaffold impeller regions “IR” due to breaks or discontinuities in thescaffold pattern in the central region. The scaffold has relatively morerigid impeller sections “IR” adjacent the central region where impellersmay be disposed (not shown). The relatively increased rigidity in theimpeller regions IR may help maintain tip gap and impellerconcentricity. This pump scaffold pattern provides for a flexibilitydistribution, along its length, of a proximal section of relatively lessflexibility (“IR”), a central region “CR” of relatively higherflexibility, and a distal section “IR” of relatively less flexibilitythan the central region. The relatively less flexible sections (i.e.,the two IR regions) are where proximal and distal impellers may bedisposed (not shown but other embodiments are fully incorporated hereinin this regard), with a relatively more flexible region in between.Exemplary benefits of the relative flexibility in these respectivesections are described elsewhere herein. FIG. 11 is an example of ascaffold that is continuous from a first end region to a second endregion, even though there are breaks or discontinuities in somelocations of the scaffold. There is at least one line that can be tracedalong a continuous structural path from a first end region to a secondend region.

The following disclosure provides exemplary method steps that may beperformed when using any of the blood pumps, or portions thereof,described herein. It is understood that not all of the steps need to beperformed, but rather the steps are intended to be an illustrativeprocedure. It is also intended that, if suitable, in some instances theorder of one or more steps may be different. Before use, the blood pumpcan be prepared for use by priming the lumens (including any annularspaces) and pump assembly with sterile solution (e.g., heparinizedsaline) to remove any air bubbles from any fluid lines. The catheter,including any number of purge lines, may then be connected to a console.Alternatively, the catheter may be connected to a console and/or aseparate pump that are used to prime the catheter to remove air bubbles.

After priming the catheter, access to the patient's vasculature can beobtained (e.g., without limitation, via femoral access) using anappropriately sized introducer sheath. Using standard valve crossingtechniques, a diagnostic pigtail catheter may then be advanced over a,for example, 0.035″ guide wire until the pigtail catheter is positionedsecurely in the target location (e.g., left ventricle). The guidewirecan then be removed and a second wire 320 (e.g., a 0.018″ wire) can beinserted through the pigtail catheter. The pigtail catheter can then beremoved (see FIG. 12A), and the blood pump 321 (including a catheter,catheter sheath, and pump portion within the sheath; see FIG. 12B) canbe advanced over the second wire towards a target location, such asspanning an aortic valve “AV,” and into a target location (e.g., leftventricle “LV”), using, for example, one or more radiopaque markers toposition the blood pump.

Once proper placement is confirmed, the catheter sheath 322 (see FIG.12C) can be retracted, exposing first a distal region of the pumpportion. In FIG. 12C a distal region of an expandable housing has beenreleased from sheath 322 and is expanded, as is distal impeller 324. Aproximal end of housing 323 and a proximal impeller are not yet releasedfrom sheath 322. Continued retraction of sheath 322 beyond the proximalend of housing 323 allows the housing 323 and proximal impeller 325 toexpand (see FIG. 12D). The inflow region (shown with arrows even thoughthe impellers are not yet rotating) and the distal impeller are in theleft ventricle. The outflow (shown with arrows even though the impellersare not rotating yet) and proximal impeller are in the ascending aortaAA. The region of the outer housing in between the two impellers, whichmay be more flexible than the housing regions surrounding the impellers,as described in more detail herein, spans the aortic valve AV. In anexemplary operating position as shown, an inlet portion of the pumpportion will be distal to the aortic valve, in the left ventricle, andan outlet of the pump portion will be proximal to the aortic valve, inthe ascending aorta (“AA”).

The second wire (e.g., an 0.018″ guidewire) may then be moved prior tooperation of the pump assembly (see FIG. 12E). If desired or needed, thepump portion can be deflected (active or passively) at one or morelocations as described herein, as illustrated in FIG. 12F. For example,a region between two impellers can be deflected by tensioning atensioning member that extends to a location between two impellers. Thedeflection may be desired or needed to accommodate the specific anatomy.As needed, the pump portion can be repositioned to achieve the intendedplacement, such as, for example, having a first impeller on one side ofa heart valve and a second impeller on a second side of the heart valve.It is understood that in FIG. 12F, the pump portion is not in any wayinterfering or interacting with the mitral valve, even if it may appearthat way from the figure.

As set forth above, this disclosure includes catheter blood pumps thatinclude an expandable pump portion extending distally relative to acatheter. The pump portions include an impeller housing that includes anexpandable blood conduit that defines a blood lumen. The blood conduitmay include one or more scaffold sections that together may also bereferred to herein as a single scaffold. In some exemplary embodimentsthe expandable blood conduit may include one or more of a proximalimpeller scaffold, a distal impeller scaffold, and a central scaffolddisposed between the proximal impeller scaffold and the distal impellerscaffold, where any combination thereof may also be referred to hereinas a scaffold. Any individual proximal impeller scaffold or distalimpeller scaffold may also be referred to herein as an expandablemember, such as is shown in FIGS. 3A-3D. In some embodiments theexpandable blood conduit may include a proximal impeller scaffold andadditional scaffold extending distally therefrom, such as if the pumpportion includes a proximal impeller but does not include a distalimpeller. In any of the embodiments herein, a reference to a distalimpeller is only by way of example, and pump portions herein need notinclude a distal impeller. Central scaffolds herein are generally lessstiff in response to a radially inward force than a proximal scaffold,and optionally also less stiff than a distal scaffold, such as a distalimpeller scaffold. Exemplary advantages of central scaffold sectionsthat are less stiffness are set forth elsewhere herein. The bloodconduit may also include a membrane coupled to the one or morescaffolds, the membrane at least partially defining the blood lumen.Membranes in this context may incorporate by reference herein thedisclosure of conduits, including any feature or method of manufacturingdescribed above. The catheter blood pumps may include an impellerdisposed in a proximal region of the impeller housing, which may be aproximal impeller. The catheter blood pumps may also include a distalimpeller in a distal region of the impeller housing. Exemplaryimpellers, including exemplary proximal and distal impellers, are setforth herein by way of example. An impeller that is at least partiallywithin a portion of a scaffold may be described with respect to therelative position of the scaffold, such as a proximal impeller within atleast a portion of a proximal scaffold, or a distal impeller within atleast a portion of a distal scaffold.

When a proximal impeller is described as being within a proximalscaffold, it is understood that the proximal scaffold need not axiallyextend over an entire length of the impeller, as long as there is someamount of axial overlap. For example, some proximal impellers hereinextend proximally from a blood conduit, and a proximal region of theproximal impeller is not surrounded by a blood conduit scaffold, while adistal region of the impeller is surrounded by scaffold. Similarly, whena distal impeller herein (if the pump includes a distal impeller) isdescribed as being within a distal scaffold, it is understood that thedistal scaffold need not axially extend over an entire length of theimpeller, as long as there is some degree of axial overlap therebetween.

FIGS. 13A-17 illustrate exemplary designs for expandable scaffoldsherein, which may at least partially surround an impeller that is atleast partially disposed within a conduit that creates a fluid lumen.The scaffold patterns in FIGS. 13A-17 may be scaffold patterns that onlyextend over a particular impeller (e.g., a proximal basket or distalbasket), or they may be scaffold patterns that extend over an entireblood conduit scaffold.

FIGS. 13A-17 illustrate expandable support members or scaffolds thateach have an expanded configuration, wherein in the expandedconfiguration the support member has a plurality of continuous axiallyextending elements (e.g., 408, 410, 420, 430, 440) that are continuousand axially extending over at least 50% of a length of the expandablesupport member (e.g., L_(s)), and wherein the expandable support memberincludes a plurality of sets of connectors (e.g., 412/414, 409, 422/424,432/434, 442/444) each set of connectors extending between first andsecond circumferentially adjacent continuous axially extending elements.In some embodiment the axially extending elements are linear orsubstantially linear.

FIGS. 13A-13C illustrate an exemplary pump portion 400 or a portionthereof that comprises an expandable impeller housing 402, wherein theexpandable impeller housing having a blood conduit 404, the conduitdefining a blood lumen between an housing inflow “I” and a housingoutflow “0”. The expandable impeller housing also includes an expandablescaffold or support member 406 at least partially surrounding animpeller (not shown in FIGS. 13A-13C) that is at least partiallydisposed within the conduit. FIGS. 14A-17 illustrate an expandablescaffold of the pump portion. It is understood that any expandablescaffold in any of FIGS. 13A-17 may be used in place of any expandablescaffold herein. Impeller housing 402 may illustrate the entire impellerhousing, or it may only represent only a portion thereof, including onlya single scaffold section, such as with any of the multi-impellerdesigns herein. It is thus understood that the structure shown in FIGS.13A-C may only be a portion of the expandable housing of a pump portion.For example, a pump portion may include two of the expandable scaffoldsections shown in FIGS. 13A-C, axially spaced apart, and coupled by aflexible membrane, for example.

FIGS. 13A-C illustrate an expandable impeller housing that includes aplurality of axially extending elements 408 circumferentially spacedapart around the housing 402 from adjacent axially extending elements,as shown. FIGS. 13A and 13B show an expanded configuration of thehousing, while FIG. 13C illustrates a model of a flat, unexpandedconfiguration with unitary struts 401 extending axially therefrom, asshown. The plurality of axially extending elements may be referred to as“elements” in the context of scaffolds for simplicity, but it isunderstood that they are not to be considered any other type of“element” herein unless specifically indicated as such. The elements inthis embodiment may be axial and linear in the housing expandedconfiguration. Expandable scaffold 406 also includes circumferentialconnectors 409 that circumferentially connect adjacent axial elementsand extend from one axial element to an adjacent axial element. In thisexemplary embodiment all of the connectors have the same generalconfiguration, which includes first and second segments meeting at arounded peak that is oriented axially (proximally or distally dependingon the reference frame), otherwise stated as pointing axially. Length Lsof the scaffold and length Le of the elements is illustrated in FIG.13C. Optional struts 401 are shown (which may be unitary with thescaffold). The axial elements 408 in this embodiment extend from a firstaxial element end 405 to second axial element end 405′, which extendalmost the entire length of the scaffold Ls. As shown, ends 405′ of theelements (only one labeled) extend to a distal end region 407′ of thescaffold 406. End 405 extends to proximal end region 407. The pumpportion also includes a transition region 411, which includescircumferential extensions of adjacent axial elements, after which theymeet to form a strut 401, as shown.

FIG. 14A (expanded) and 14B (unexpanded) illustrate an exemplaryexpandable scaffold 406′, which includes a plurality of axiallyextending elements 410. A first set of connectors 412 have “S”configurations, and a second circumferentially adjacent set ofconnectors 414 have inverse (reverse) “S” shapes. In the expandedconfiguration in FIG. 14A the axial elements 410 may be linear, or theymay have a slight curvilinear configuration as shown. Scaffold 406′includes transition region 411′, which may have similar features to thetransition region 411 herein. The relevant description from any otherembodiment may be incorporated with the scaffold in FIGS. 14A-B (e.g.,lengths of scaffold or support member and axial elements, transitionregion, etc.). Some of the optional struts 413 are shown, as are ends405/405′ of the axial elements. Scaffold 406′ may be proximal or distalscaffold, or it may extend along the length of the impeller housing.

FIGS. 15A and 15B illustrate an exemplary expandable scaffold 406″ thatis similar to those in FIGS. 13, 14, 16, and 17. Axially extendingelements 420 are shown, adjacent ones of which are connected bycircumferential connectors 422 and 424, ends of which are axiallyoffset. A first set of connectors 422 has a general S configuration,while a second set of connectors 424 are reverse S-shaped. In thisembodiments the axially extending elements 420 are curvilinear, asshown. The pattern of S and inverse-S alternates around the expandablemember, as it does in the scaffolds in FIGS. 14A and 14B. Scaffold 406″also includes a transition region 421, examples of which are describedelsewhere herein. Scaffold 406″ may be proximal or distal scaffold, orit may extend along the length of the impeller housing.

FIG. 16 illustrates a collapsed (unexpanded) configuration of anexemplary scaffold 406′″, which may have any other suitable features ofany other support member or scaffold herein. Axially extending elements430 are shown, connected by first set of S-shaped connectors 434 and asecond set of inverse-S shaped connectors 432. The pattern of S andinverse-S shapes alternates circumferentially around the scaffold 406′″as shown. Scaffold 406′″ may be proximal or distal scaffold, or it mayextend along the length of the impeller housing.

FIG. 17 illustrates a collapsed (unexpanded) configuration of anexemplary scaffold 406″″, which may have any other suitable features ofany other support member or scaffold herein. Axially extending elements440 are shown, connected by inverse-S shaped connectors. All sets of theconnectors in this embodiment (e.g., set 442 and set 444) have the sameconfiguration, and in this embodiment are all inverse-S shaped.Exemplary struts are shown axially disposed relative to the scaffold406″″, and the scaffold 406″″ may include transition sections which aredescribed elsewhere herein. Scaffold 406″″ may be a proximal scaffold ora distal scaffold, or it may extend along the length of the impellerhousing.

The scaffolds and blood conduit embodiments in FIGS. 13A-17 areillustrative, and may be modified to include aspects of otherembodiments herien. The following description may provide modificationsto the scaffolds in FIGS. 13A-17, any of which may be incorporated intoany of the scaffolds in FIGS. 13A-17.

In any of the scaffolds shown in FIGS. 13A-17, at least a first end ofeach of the plurality of axially extending elements may extend to one ormore of a proximal end region (e.g., 417′, 407′) and a distal end region(e.g., 417) of the expandable scaffold.

In any of the scaffolds shown in FIGS. 13A-17, at least one of, andoptionally all of, the plurality of axially extending elements may belinear. In any of the scaffolds shown in FIGS. 13A-17, at least one of,and optionally all of, the plurality of axially extending elements maybe curvilinear.

In any of the scaffolds shown in FIGS. 13A-17, each one of the theplurality of axially extending elements may have proximal and distalends, wherein the proximal and distal ends are substantiallycircumferentially aligned.

In any of the scaffolds shown in FIGS. 13A-17, each of the the pluralityof axially extending elements may have a circumferential span(illustrated as “CS” in FIG. 15A) that is not larger than 10 degreescircumferentially around the expandable scaffold, optionally not largerthan 5 degrees of the expandable scaffold.

In any of the scaffolds shown in FIGS. 13A-17, each of the the pluralityof axially extending elements may follow a path that is substantiallyparallel with a longitudinal axis of the expandable scaffold.

In any of the embodiments in FIGS. 13A-17, each of the the plurality ofaxially extending elements may be continuous and axially extending overat least 55% of a length of the expandable scaffold, optionally over atleast 60%, optionally over at least 65%, optionally over at least 70%,optionally over at least 75%, optionally over at least 80%, optionallyover at least 85%, optionally over at least 90, optionally over at least95.

In any of the scaffolds shown in FIGS. 13A-17, all of the connectors inall of the sets of the plurality of sets of connectors may have the sameconfiguration. In any of the scaffolds shown in FIGS. 13A-17, all of theconnectors in all of the sets of the plurality of sets of connectors maynot have the same configuration. In any of the scaffolds shown in FIGS.13A-17, each individual set of connectors may have a plurality ofconnectors that have the same configuration. In any of the embodimentsin FIGS. 13A-17, all of the connectors in all of the sets of theplurality of sets of connectors may have an S-shape. In any of theembodiments in FIGS. 13A-17, all of the connectors in all of the sets ofthe plurality of sets of connectors may have a reverse (or inverted)S-shape. In any of the scaffolds shown in FIGS. 13A-17, all of theconnectors in a first set of connectors may have a S shape. In any ofthe scaffolds shown in FIGS. 13A-17, a second set of connectors that iscircumferentially adjacent to the first set of connnectors may all havean inverted S shape. In any of the scaffolds shown in FIGS. 13A-17, Sshape/inverted S shape connectors may alternate around the circumferenceof the expandable scaffold.

In any of the embodiments in FIGS. 13A-17, a first set of connectorsthat extend in a first circumferential direction from a first axiallyextending element may extend from the first axially extending element ataxial locations that are different from the axial locations at which asecond set of connectors extend from the first axially extending elementin a second circumferential direction (i.e., the connectors have endsthat are axially offset).

In any of the embodiments in FIGS. 13A-17, the expandable scaffold mayinclude a transition region connecting a first axially extending elementwith a strut, optionally wherein the transition region is consideredpart of the expandable scaffold. A transition region may also connectthe strut with a second axially extending element, the second axiallybeing circumferentially adjacent to the first axially extending aroundthe blood conduit. In any of the scaffolds shown in FIGS. 13A-17, theexpandable scaffold may extend along substantially the entire length ofthe conduit. In any of the scaffolds shown in FIGS. 13A-17, theexpandable scaffold may extend along less than 50% of the length of theexpandable impeller housing. In any of the embodiments in FIGS. 13A-17,the expandable scaffold may extend only in a region of the expandablehousing in which an impeller is disposed.

In any of the embodiments in FIGS. 13A-17, the expandable impellerhousing may include a second expandable scaffold axially spaced from thefirst expandable scaffold. A second expandable scaffold may have anexpanded configuration with a second plurality of axially extendingelements that are axially extending over at least 50% of a length of thesecond expandable scaffold and wherein the second expandable scaffoldmay also include a plurality of sets of connectors, each set ofconnectors extending circumferentially between first and secondcircumferentially adjacent axially extending elements. A secondexpandable scaffold may include any features set forth in any of theclaims or described elsewhere herein. In any of the scaffolds shown inFIGS. 13A-17, the expandable scaffold may be unitary, that is, made froma single piece of starting material.

FIGS. 18A and 18B illustrate an exemplary scaffold 450 comprising aplurality of axially extending elements 452 (eight in this example).Scaffold 450 includes a proximal scaffold 460, a central scaffold 462,and distal scaffold 464. In this example axially extending elements 452are linear. Central scaffold 462 is connected to proximal scaffold 460and to distal scaffold 464 in this example, and in particular, isunitary with them in this example. FIG. 18B illustrates an expandedconfiguration, and FIG. 18A illustrates an as-cut flat illustration ofthe scaffold. The axially extending elements 452 that are labeled inFIG. 18B are circumferentially adjacent axial elements. Adjacent axiallyextending elements are connected by a plurality of circumferentialconnectors 451, which in this example have general S or inverse-Sconfigurations, which include at least one bend formed therein. Asshown, each circumferential connector is circumferentially adjacent toanother circumferential connectors, and together they extend around theblood conduit. In this example, as shown, circumferentially adjacentcircumferential connectors are displaced axially relative to oneanother. For example, circumferential connectors 451′ are axiallydisplaced (or axially offset) relative to circumferential connectors451″. Axially displaced or axially offset in this context refers toproximal ends of the connectors being axially offset, distal ends of theconnectors being axially offset, or both. In this example, a section ofeach one of the axially extending elements connects adjacentcircumferential connectors that are axially displaced. For example,section 453 of one of the axially extending elements 452 connectscircumferential connector 451′ and 451″, which creates the axiallydisplaced nature of the circumferentially adjacent circumferentialconnectors. In this example, distal ends of connectors 451″ are furtherdistally than the distal ends of the circumferentially adjacentconnectors 451′, as shown. FIGS. 18A and 18B also illustrate a firstgroup of a plurality of circumferential connectors having a first axialposition, and a second group of the plurality of circumferentialconnectors having a second axial position, wherein the first and secondaxial positions alternate circumferentially around the blood conduit, asshown.

FIGS. 19A and 19B illustrate an exemplary scaffold 470. Scaffold 470includes a plurality of axially extending elements 472, which are linearis sections but are not linear along the entire scaffold 470 length.Scaffold 470 also includes connectors 471 that circumferentially connectcircumferentially adjacent axial elements 472. Connectors 471 includespeaks that are oriented, or point, axially, and in this example may beoriented distally or proximally. Scaffold 470 includes a proximalscaffold, a central scaffold, and a distal scaffold that are connected,and in this example are unitary, just as with the scaffold in FIGS. 18Aand 18B. Both the proximal scaffold, central scaffold, and distalscaffold comprise a plurality of linear axially extending elementsspaced apart around the blood conduit, wherein first and second adjacentlinear axially extending elements are each connected by acircumferential connector having at least one bend formed therein. Thecircumferential connectors defining a plurality of circumferentialconnectors around the blood conduit, and wherein circumferentiallyadjacent circumferential connectors of the plurality of circumferentialconnectors are displaced axially relative to one another. Like in FIGS.18A and 19B, a section 473 of each one of the axially extending elements(in this example linear) connects circumferentially adjacentcircumferential connectors that are axially displaced, as shown. FIGS.19A and 19B illustrate a first group of a plurality of circumferentialconnectors having a first axial position, and wherein a second group ofthe plurality of circumferential connectors have a second axialposition, wherein the first and second axial positions alternatecircumferentially around the blood conduit. In this embodiment, theproximal, central, and distal scaffolds are generally have the sameconfiguration (except the ends of the distal and proximal scaffolds).

Scaffold 470 also includes second region 477 that is axially adjacentfirst region 476, wherein second region 477 comprises a plurality ofpeaks 478 that are shown oriented orthogonally relative to a long axisof the blood conduit (membrane not shown for clarity). In this example,each of the plurality of peaks 478 is an extension of one of the axiallyextending elements 472 in the first region 476, as shown. Scaffold 470also includes third region 479 that is axially adjacent second region477, the third region 470 comprising a second plurality of linearaxially extending elements as shown that are spaced apart around theblood conduit, and a second plurality of circumferential connectors 471,where the second region 477 joins the first region 476 and third region479. In this example this pattern continues along the length of thescaffold.

FIGS. 20A and 20B illustrate exemplary scaffold 500, with FIG. 20Bshowing the expanded configuration and FIG. 20A illustrating a flattenednon-expanded configuration. Features that are shown in FIGS. 20A and 20Bthat are the same as features shown in other scaffolds herein may beexpressly included in this embodiment even if not described herewith.Scaffold 500 includes proximal scaffold 510, central scaffold 520 anddistal scaffold 530, which are unitary in this embodiment. In thisembodiment the central scaffold 520 has a pattern and configuration suchthat it is less stiff in response to a radially inward force thanproximal scaffold 510 and distal scaffold 530. Proximal scaffold 510 maybe a proximal impeller scaffold, and distal scaffold 530 may be a distalimpeller scaffold, within at least a portion of which a proximalimpeller and a distal impeller may be disposed, respectively. Scaffold500 central scaffold 520 has a pattern that is different than thepattern in scaffold sections 510 and 530. In this example, scaffoldsections 510 and 530 have patterns that are substantially the same.Scaffold 500 includes circumferential connectors in proximal scaffold510, central scaffold 520, and distal scaffold 530, as shown. Forexample, proximal scaffold 510 includes circumferential connectors 512,and distal scaffold 530 includes circumferential connectors 532. Thecircumferential connectors in scaffold 500 have the same configurationsas circumferential connectors 451 in the scaffold 450 in FIGS. 18A and18B, and all descriptions thereof are incorporated by reference with thecircumferential connectors into all scaffold sections in scaffold 500.For example only, circumferentially adjacent circumferential connectorsare axially displaced (i.e., axially offset) relative to one another,which is described in more detail elsewhere herein. The circumferentialconnectors also have the S and inverse-S configurations, which isdescribed with respect to other scaffolds herein. The central scaffold520 in scaffold 500 also includes peaks 521 and 521′, similar to peaks478 in the scaffold in FIGS. 19A and 19B. A first plurality of peaks 521have a first axial position, and a second plurality of peaks 521′ have asecond axial position, which can be seen clearly in FIG. 20A. The axialposition alternates circumferentially around the scaffold, as shown.Peaks 521 and 521′ extend from axially extending elements 522 like thescaffold in FIGS. 19A and 19B. The proximal scaffold and the distalscaffold do not include peaks in this embodiment. Axially extendingelements 522 in the central scaffold section have a width that isgreater than the width of the scaffold in peak 521 regions, as shown.This difference in width can provide the peak regions with greaterflexibility, while the wider axially extending element providesufficient radial support in the central scaffold. Any of the scaffoldsections with the peaks may be considered a first region, and theaxially adjacent sections with circumferential connectors and axiallyextending elements may be considered second regions, examples of whichare described elsewhere herein. In this embodiment the axially extendingelements are linear as shown, but may be curvilinear in otherembodiments.

FIGS. 21A and 21B illustrate exemplary scaffold 550, with FIG. 21Bshowing the expanded configuration and FIG. 21A illustrating a flattenednon-expanded configuration. Features that are shown in FIGS. 21A and 21Bthat are the same as features shown in other scaffolds herein may beexpressly included in this embodiment even if not described herewith.Scaffold 550 includes proximal scaffold 560, central scaffold 570 anddistal scaffold 580, which are unitary in this embodiment. Proximalscaffold 560 may be a proximal impeller scaffold, and distal scaffold580 may be a distal impeller scaffold, within at least a portion ofwhich a proximal impeller and a distal impeller may be disposed,respectively. Scaffold 550 central scaffold 570 has a pattern that isdifferent than the pattern in scaffold sections 560 and 580. In thisexample, scaffold sections 560 and 580 have patterns that aresubstantially the same. Scaffold 550 includes circumferential connectorsin proximal scaffold 560, central scaffold 570, and distal scaffold 580,as shown. For example, proximal scaffold 560 includes circumferentialconnectors 562, and distal scaffold 580 includes circumferentialconnectors 582. The circumferential connectors in scaffold 550 have thesame configurations as circumferential connectors 451 in the scaffold450 in FIGS. 18A and 18B, and all descriptions thereof are incorporatedby reference with the circumferential connectors into all scaffoldsections in scaffold 550. For example only, circumferentially adjacentcircumferential connectors are axially displaced (i.e., axially offset)relative to one another, which is described in more detail elsewhereherein. The circumferential connectors also have the S and inverse-Sconfigurations, which is described with respect to other scaffoldsherein. Elements 571 in the central scaffold extend into the proximaland distal scaffold sections as shown, forming linear axially extendingelements in the proximal and distal scaffolds. Axially extendingelements 561 in proximal scaffold 560 do not extend into the centralscaffold, as shown. Similarly, axially extending elements 581 in distalscaffold 580 do not extend into the central scaffold, as shown. Elements571 in the central scaffold 570 have helical configurations as shown.Adjacent elements 571 are connected with connectors 572 as shown.Connectors 572 may have any characteristics of any circumferentialconnectors herein, such as the alternating S and inverse-Sconfigurations. FIG. 21A illustrates a flattened non-expandedconfiguration, and the scaffold 550 may be formed into the configurationshown in FIG. 21B, such as by twisting the ends relative to one anotherand setting the scaffold in the configuration shown in FIG. 21B.

FIGS. 22A and 22B illustrate exemplary scaffold 600, with FIG. 22Bshowing the expanded configuration and FIG. 22A illustrating a flattenednon-expanded configuration. Features that are shown in FIGS. 22A and 22Bthat are the same as features shown in other scaffolds herein may beexpressly included in this embodiment even if not described herewith.Scaffold 600 includes proximal scaffold 610, central scaffold 620 anddistal scaffold 630, which are unitary in this embodiment. Proximalscaffold 610 may be a proximal impeller scaffold, and distal scaffold630 may be a distal impeller scaffold, within at least a portion ofwhich a proximal impeller and a distal impeller may be disposed,respectively. Scaffold 600 central scaffold 620 has a pattern that isdifferent than the pattern in scaffold sections 610 and 630. In thisexample, scaffold sections 610 and 630 have patterns that aresubstantially the same. Scaffold 600 includes circumferential connectorsin proximal scaffold 610, central scaffold 620, and distal scaffold 630,as shown. For example, proximal scaffold 610 includes circumferentialconnectors 612, and distal scaffold 630 includes circumferentialconnectors 632. The circumferential connectors in the proximal anddistal sections of scaffold 600 have the same configurations ascircumferential connectors 451 in the scaffold 450 in FIGS. 18A and 18B,and all descriptions thereof are incorporated by reference with thecircumferential connectors into all scaffold sections in scaffold 600.For example only, circumferentially adjacent circumferential connectorsare axially displaced (i.e., axially offset) relative to one another,which is described in more detail elsewhere herein, and connect axiallyextending elements 611 and 631, respectively. The circumferentialconnectors also have S and inverse-S configurations, which is describedwith respect to other scaffolds herein. Axially extending elements 621in the central scaffold extend into the proximal and distal scaffoldsections as shown, wherein the elements 621 are linear axially extendingelements in the proximal and distal scaffolds as well as the centralscaffold. Axially extending elements 611 in proximal scaffold 610 do notextend into the central scaffold, as shown. Similarly, axially extendingelements 631 in distal scaffold 630 do not extend into the centralscaffold, as shown. Elements 621 in the central scaffold 620 haveaxially extending linear configurations as shown. Central scaffold 620includes axially extending elements 621 that are connected bycircumferential connectors. The circumferential connectors include aplurality of axially extending elements 624, each of which connectcircumferentially adjacent circumferential connectors 622, as shown.When scaffold 600 is expanded to the configuration shown in FIG. 22B,the circumferential connectors assume the configuration shown, whereinelements 624 are no longer purely axially extending, such that they forman angle with a long axis of the scaffold, as shown.

FIGS. 23A and 23B illustrate exemplary scaffold 650, with FIG. 23Bshowing the expanded configuration and FIG. 23A illustrating a flattenednon-expanded configuration. Features that are shown in FIGS. 23A and 23Bthat are the same as features shown in other scaffolds herein may beexpressly included in this embodiment even if not described herewith.Scaffold 650 includes proximal scaffold 660, central scaffold 670 anddistal scaffold 650, which are unitary in this embodiment. Proximalscaffold 660 may be a proximal impeller scaffold, and distal scaffold650 may be a distal impeller scaffold, within at least a portion ofwhich a proximal impeller and a distal impeller may be disposed,respectively. Scaffold 650 central scaffold 670 has a pattern that isdifferent than the pattern in scaffold sections 660 and 680. In thisexample, scaffold sections 660 and 680 have patterns that aresubstantially the same. Scaffold 650 includes circumferential connectorsin proximal scaffold 660, central scaffold 670, and distal scaffold 680,as shown. For example, proximal scaffold 660 includes circumferentialconnectors 662, and distal scaffold 650 includes circumferentialconnectors 682. The circumferential connectors in the proximal anddistal sections of scaffold 650 have the same configurations ascircumferential connectors 451 in the scaffold 450 in FIGS. 18A and 18B,and all descriptions thereof are incorporated by reference with thecircumferential connectors into all scaffold sections in scaffold 650.For example only, circumferentially adjacent circumferential connectorsare axially displaced (i.e., axially offset) relative to one another,which is described in more detail elsewhere herein, and connect axiallyextending elements 661 and 681, respectively. The circumferentialconnectors also have S and inverse-S configurations, which is describedwith respect to other scaffolds herein. Axially extending elements 671in the central scaffold extend into the proximal and distal scaffoldsections as shown, wherein the elements 671 are linear axially extendingelements in the proximal and distal scaffolds as well as the centralscaffold. Axially extending elements 661 in proximal scaffold 660 do notextend into the central scaffold, as shown. Similarly, axially extendingelements 681 in distal scaffold 650 do not extend into the centralscaffold, as shown. Elements 671 in the central scaffold 670 haveaxially extending linear configurations as shown. Central scaffold 670includes axially extending elements 671 that are connected bycircumferential connectors. The circumferential connectors include aplurality of axially extending elements 674, each of which connectcircumferentially adjacent circumferential connectors 672, as shown.When scaffold 650 is expanded to the configuration shown in FIG. 23B,the circumferential connectors 672 assume the configuration shown,wherein elements 674 are no longer purely axially extending, such thatthey form an angle with a long axis of the scaffold, as shown. Elements674 in FIG. 23A are formed by removing material axially disposed betweenaxially adjacent elements 674.

FIGS. 24A and 24B illustrate exemplary scaffold 700, with FIG. 24Bshowing the expanded configuration and FIG. 24A illustrating a flattenednon-expanded configuration. Features that are shown in FIGS. 24A and 24Bthat are the same as features shown in other scaffolds herein may beexpressly included in this embodiment even if not described herewith.For example, scaffold 700 is the same in some ways to the scaffoldsshown in FIGS. 19A, 19B, 20A and 20B. Scaffold 700 includes proximalscaffold 710, central scaffold 720 and distal scaffold 730, which areunitary in this embodiment. Proximal scaffold 710 may be a proximalimpeller scaffold, and distal scaffold 730 may be a distal impellerscaffold, within at least a portion of which a proximal impeller and adistal impeller may be disposed, respectively. Scaffold 700 centralscaffold 720 has a pattern that is different than the pattern inscaffold sections 710 and 730. In this example, scaffold sections 710and 730 have patterns that are substantially the same. Scaffold 700includes circumferential connectors in proximal scaffold 710, in centralscaffold 720, and in distal scaffold 730, as shown. For example,proximal scaffold 710 includes circumferential connectors 712, anddistal scaffold 730 includes circumferential connectors 732. Thecircumferential connectors in the proximal and distal sections ofscaffold 700 have the same configurations as circumferential connectors451 in the scaffold 450 in FIGS. 18A and 18B, and all descriptionsthereof are incorporated by reference with the circumferentialconnectors into all scaffold sections in scaffold 700. For example only,circumferentially adjacent circumferential connectors are axiallydisplaced (i.e., axially offset) relative to one another, which isdescribed in more detail elsewhere herein, and connect axially extendingelements 711 and 731, respectively. The circumferential connectors alsohave S and inverse-S configurations alternating circumferentially aroundthe scaffold, which is described with respect to other scaffolds herein.Scaffold 700 includes a plurality of axially extending elements 711,which are linear in sections but do not extend along the entire lengthof scaffold 700. Scaffold 700 also includes circumferential connectors712 that circumferentially connect circumferentially adjacent axialelements 711. The proximal scaffold, central scaffold, and distalscaffold comprise a plurality of linear axially extending elements 711,721, and 731, respectively, that are circumferentially spaced apartaround the respective scaffold section, wherein first and secondadjacent linear axially extending elements are each connected by acircumferential connector 712, 722, and 732, respectively, having atleast one bend formed therein. The circumferential connectors define aplurality of circumferential connectors around the scaffold, and whereincircumferentially adjacent circumferential connectors of the pluralityof circumferential connectors are displaced axially relative to oneanother, as shown and described elsewhere herein. As is the case inFIGS. 18A and 19B, a section of each one of the axially extendingelements (in this example linear elements) connects circumferentiallyadjacent circumferential connectors that are axially displaced, asshown. FIGS. 24A and 24B illustrate a first group of a plurality ofcircumferential connectors having a first axial position, and wherein asecond group of the plurality of circumferential connectors have asecond axial position, wherein the first and second axial positionsalternate circumferentially around the scaffold.

Scaffold 700 also includes a second region that is axially adjacent afirst region, wherein the second region comprises a plurality of peaks724 that are shown oriented orthogonally relative to a long axis of thescaffold 700. In this example, each of the plurality of peaks 724 is anextension of one of the axially extending elements 721, as shown.Scaffold 700 also includes a third region that is axially adjacent thesecond region, the third region comprising a second plurality of linearaxially extending elements as shown that are spaced apart around thescaffold, and a second plurality of circumferential connectors 722,where the second region joins the first region and third region. In thisembodiment, the second region includes first convex section 725 andsecond convex section 727, connected at location 729.

FIGS. 25A and 25B illustrate an exemplary scaffold 750, which in thisexample includes a proximal scaffold 760, central scaffold 770 anddistal scaffold 780, which are unitary. Scaffold 750 is similar inseveral ways to scaffold 700 in FIGS. 24A and 24B, the disclosure ofwhich is completely incorporated by reference in the description ofFIGS. 25A and 25B, any features of which may be included in scaffold750. One difference is that scaffold 750 central scaffold 770 includes afirst region that includes peaks 774, wherein the first region includessections 775 and 777 connected at location 779, wherein sections 775 and777 create a smoother curvilinear region than sections 725 and 727 inscaffold 700. An additional difference is that scaffold 750 includesproximal and distal scaffolds that both include mirrored sections, suchas sections 763 and 765 as shown in FIG. 25B. The mirrored aspect refersto axially adjacent connectors 762 in section 763 that are mirrored withrespect to connectors 762 in section 765. The same mirrored aspect isshown in distal scaffold 780. The mirrored sections in proximal scaffold760 are closer to central scaffold 770 than the mirrored sections indistal scaffold 780, as shown. In alternative embodiments, mirroredsections in a distal scaffold may be closer to a central scaffold thanmirrored sections in a proximal scaffold. The description of all otheraspects of scaffolds herein, including axially extending elements andcircumferential connectors, are incorporated by reference herein intothe scaffold 750. FIG. 25B shows a flat expanded configuration, whileFIG. 25A shows a flat non-expanded configuration.

FIGS. 26A and 26B illustrate scaffold 800, which as shown includes manyof the same features as scaffold 750 shown in FIGS. 25A and 25B. FIG.26A illustrate a flattened unexpanded configuration, while FIG. 26Billustrates transition region 801 of scaffold 800 called out in FIG.26A. A difference between the scaffolds is that in FIGS. 26A and 26B,proximal scaffold 810 includes mirrored sections that are further fromcentral scaffold 820 than mirrored section in distal scaffold, as shown.FIG. 26B illustrates a transition region between proximal scaffold 810and central scaffold 820. Scaffold 800 includes orthogonally orientedpeaks 824 as described elsewhere herein. Scaffold first regions includessections 825 and 827, which may be the same as sections 775 and 777 inscaffold 750. FIG. 26B illustrates the widths of axially extendingelements 811 being greater than the widths of elements 821 in centralscaffold, as shown. The thickness measurements are into the page in thefigures (in the “z” direction), while the width measurements are in theplane of the page in the figures shown. One thickness “t” of element 811is labeled for reference. As shown, the thickness “t” of element 811 isgreater than the thickness of elements 821 in the central scaffoldsection.

FIGS. 27A and 27B illustrate exemplary scaffold 850, which is similar inseveral ways to scaffold 550 shown in FIGS. 21A and 21B. Scaffold 850includes proximal scaffold 860, central scaffold 870 and distal scaffold880, which in this embodiment may be unitary. Scaffold 850 centralscaffold 870 includes helical elements 871 in the non-collapsedconfiguration (FIG. 27A) and the wrapped configuration (FIG. 27B). Inthis and any other embodiment herein the scaffold may be manufactured(e.g., including laser cutting of a tubular member) such that theexpanded configuration is the configuration is which the scaffold islaser-cut from the tubular member. This is in contrast to any examplesherein in which the scaffold is laser cut from a smaller diametertubular member, and then expanded and set into an expandedconfiguration. In any of the embodiments herein, a laser cut diametermay be equal to a non-collapsed diameter to, for example withoutlimitation, provide better concentricity. This may also allow coating ofa membrane to adhere to struts and have a smoother inner diameter.

Proximal scaffold 860 and distal scaffold 880 have substantial the sameconfiguration, but they are displaced circumferentially bycircumferential spacing “CS” (labeled in FIG. 27A). Adjacent helicalelements 871 are connected by connectors 872. All other similar aspectof other scaffolds herein may be incorporated herein, including, by wayof example only, the axially offset nature of circumferentially adjacentcircumferential connectors in proximal scaffold 860 and distal scaffold880.

FIG. 27A illustrates exemplary distal and proximal struts extendingaxially from the scaffold, only one strut of which 865 is labeled. Inthis example there are four proximal and four distal struts. As shown,the struts are tapered and are wider at ends further from the scaffold,which may increase stability over the impellers compared to struts thathave a constant width over their entire length. Any of the pump portionsherein may include any number of struts that have the same configurationas struts 865.

In any of the embodiments herein, the scaffold may be cut from a tubularmember that has an expanded scaffold diameter. In these embodiments, thetubular member has a diameter that is the same or substantially the sameas the desired scaffold deployed configuration (un-sheathed).Alternatively, in any of the embodiments herein, the scaffold may be cutfrom a tubular member that has a non-expanded scaffold diameter. In thisembodiments, the tubular member has a diameter less than a scaffoldexpanded diameter, and after being cut the scaffold may be expanded setin the expanded deployed configuration.

In any of the embodiments herein, a distal scaffold may have a lengththat is greater than a length of a proximal scaffold. In any of theembodiments herein, a distal scaffold may have a length that is lessthan a length of a proximal scaffold. In any of the embodiments herein,a distal scaffold may have a length that is the same as a length of aproximal scaffold.

In any embodiment herein, a central scaffold may have a length that isgreater than a length of one or both of a proximal scaffold and a distalscaffold.

Any of the different scaffold sections herein may be connected with oneor more welds, and may not be unitary with each other.

In any of the embodiments herein, any section or sections of thescaffold may have a thickness (measured radially between a scaffoldinner diameter and a scaffold outer diameter) that is the same as ordifferent than a thickness of any other section of the scaffold. Forexample, a thickness of a scaffold section may be decreased byelectropolishing one or more sections more than other sections (whichmay include no electropolishing). Varying the thickness may be inaddition to or alternative to varying the width, which may allow formore design options, as may be desired.

In any of the embodiments herein, an axial distance between proximal anddistal scaffold sections may be from 30 mm to 50 mm, such as from 35 mmto 45 mm.

In any of the embodiments herein, the pump portion may be from 40 mm and80 mm, such as from 50 mm to 70 mm, such as from 55 mm to 65 cm.

In any of the embodiments herein that include first and secondimpellers, an axial distance between impellers may be from 40 mm to 60mm, such as from 45 mm to 55 mm.

In any of the embodiments herein, a diameter of the expanded (ornon-collapsed) blood conduit may be from 6 mm to 8.5 mm, such as from 6mm to 8 mm, such as from 6.5 mm to 7.5 mm

In any of the embodiments herein, a diameter of any of the impellerswhen expanded may be from 5 mm to 7 mm, such as from 5.5 mm to 6.5 mm.

Some of the pump portions herein include a collapsible and expandableblood conduit, and one or more impellers at least partially disposed inthe blood conduit when the pump portion is in an operational state. Insome embodiments herein, the collapsible blood conduit includes ascaffold, which may extend along at least a portion of the length of theblood conduit and provide radial support to the blood conduit. In someembodiments herein a scaffold may be unitary along the blood conduit. Insome embodiments different scaffold sections may not be unitary (formedfrom the same starting material), but they may be directly attached orconnected to each other (e.g., welded directly together).

The disclosure also includes catheter blood pumps that include one ormore sensors thereon or therein, their methods of manufacture, and use.For example only, any blood pumps herein may include one or more sensorsconfigured to sense pressure. A sensor configured to sense bloodpressure may be included on an intravascular blood pump for a variety ofpurposes, such as, for example without limitation, estimating flow ordetecting the position of the blood pump. Additionally, for example, oneor more sensors may be axially spaced apart (e.g., one near an inflowand one near an outflow) and used to determine a differential pressureacross the pump portion.

FIG. 28 illustrates an exemplary catheter blood pump 1750 including anexpandable and collapsible pump portion 1751 (shown expanded ordeployed) disposed distally relative to an elongate body 1755, the pumpportion including an expandable impeller housing 1761 that includes ablood conduit that defines a blood lumen between an inflow “I” and anoutflow “0”. The pump portion includes one more impellers, any of whichmay at least partially be disposed axially within the fluid lumen(impellers are not shown in FIG. 29 for clarity). Expandable impellerhousing 1761 includes a sensor wire housing 1760 extending at leastpartially along a length of the expandable impeller housing. Pumpportion 1751 also includes a sensor wire (e.g., a fiber optic) securedto a sensor, with the sensor wire housing secured relative to theexpandable impeller housing. The sensor wire is disposed within thesensor wire housing 1760, and the sensor wire may be sized such that itfloats within a sensor wire lumen defined by the sensor wire housing. Asused herein, a sensor wire housing generally defines a sensor wirelumen, in which a sensor wire may be disposed. This disclosure may,however, use the phrases sensor wire lumen and sensor wire housinginterchangeably, however, the lumen is generally considered the spacewithin a structural housing. Expandable impeller housings herein mayalso be referred to as expandable housings herein.

In the embodiment in FIG. 28, sensor wire housing 1760 (which defines alumen therein) has a helical configuration along at least a portion ofthe expandable housing 1761, and it may have a helical configurationalong as at least 50% of a length of the expandable housing, 55%, 60%,65%, 70%, 75%, 80%, 85%, 90%, 95%, or 100% of a length of the expandablehousing.

The sensor wire housings herein may have a linear configuration along atleast a portion of the expandable housing, such as at least 50% of alength of the expandable housing, 55%, 60%, 65%, 70%, 75%, 80%, 85%,90%, 95%, or 100% of a length of the expandable housing.

The sensor wire housings herein may have a helical configuration along aportion of its length, and may have linear or other configurations alongother portions of its length. The sensor wire housings herein may havehelical configurations in one or more discrete axially spaced helicalregions, and optionally may have linear configurations in one or morediscrete axially spaced linear regions. Sensor wire housings may haveother non-linear and non-helical configurations as well.

The sensor wire housings herein generally help protect the one or moresensor wires (e.g., fiber optic). Sensors wires (e.g., fiber optics) maybe quite fragile and susceptible to breaking, especially when the pumpportion is navigated through curved vasculature and bends. Sensor wirehousings herein can be sized relative to the sensor wire such that thesensor wire may float within the lumen, which may provide space for thewire to move slightly while the pump portion is navigated and/or in use,which may reduce the likelihood of sensor wire breakage.

In some embodiments, however, a sensor wire may be fixed relative to aimpeller housing such that it is not floating with a space. Whendescribed as being fixed relative to an impeller housing, there may besome degree of slight movement provided between a sensor wire andimpeller housing due to the flexibility of the materials, but fixed inthis context refers generally to not freely floating within an openlumen. FIG. 29 provides an illustrative cross section of expandablehousing 1765 (details of which are not shown for clarity, but mayinclude any features of any pump portion herein, such as a membrane, anexpandable support member, and impeller, etc., exemplary details ofwhich can be found elsewhere herein), with sensor wire 1766 fixedrelative thereto (not floating), and secured thereto by overlay 1767,which may be deposited on the sensor wire to secure wire 1766 relativeto housing 1765. The overlay 1767 and sensor wire 1767 may have anyconfiguration along the length of the expandable housing, such ashelical, partial helical, curvilinear, partial curvilinear, linear,partially linear, or any combination thereof.

FIG. 30 illustrates an exemplary cross section of exemplary expandableimpeller housing 1770 (again, details of which are not shown forclarity, but may include any feature of any pump portion herein, such asa membrane, an expandable support member, and impeller, etc., exemplarydetails of which can be found elsewhere herein). In this embodiment, thepump portion includes a sensor wire housing that defines a sensor wirelumen that is sized and configured relative to the sensor wire such thatthe sensor wire floats within the lumen along at least a portion of theexpandable impeller housing. In any of the embodiments that include asensor wire housing, the sensor wire may be fixed to the expandablehousing at one more discrete locations, such as at locations where thesensor wire extends out of the sensor wire housing, such as at one orboth of a proximal end or a distal end of a sensor wire housing. In theembodiment in FIG. 30, the pump portion includes a separate sensor wirehousing that defines a sensor wire lumen 1771. For example only, thesensor wire housing may be a hollow tubular element that extends alongat least a portion of the expandable housing, such as a tube. The sensorwire housings herein, in the context of sensor wire lumens, may be awide variety of materials, such as elastomeric or semi-rigid, or rigid.In any of the embodiments herein, the sensor wire housing may not imparta meaningful increase in rigidity to the expandable impeller housing atthe location of the sensor wire housing, although there may be a slightincrease in stiffness.

Any of the sensor wire housings herein that house a sensor wire may alsohave a non-circular cross sectional shape, such as rectilinear (e.g.,triangular, rectangular, square), or curvilinear (e.g., oval), or anyother non-defined, irregular, shape. In this exemplary embodiment, thesensor wire housing that defines lumen 1771 is secured to the expandablehousing 1770 at least partially by overlay 1773, and in this embodimentoverlay 1773 is disposed about a radially outermost portion of thesensor wire housing and lumen 1771. The overlay 1773 at least partiallyserves to help secure the sensor wire housing relative to the expandablehousing. In this exemplary embodiment it may be a combination of theexpandable membrane material of the housing 1770 as well as overlay 1773that together surround the sensor wire housing and help secure itrelative to the expandable housing 1770. The membrane of the expandableimpeller housing 1770 is disposed radially within sensor wire housing,and overlay 1773 is disposed about the sensor wire housing and lumen1771, including about a radially outmost portion of the sensor wirehousing as shown. In any of the embodiments herein, the expandablehousing 1770 membrane may not be in direct contact with the sensor wirehousing; there may be one or more layers of overlay material in betweenthe two.

Any of the overlays herein may be different than an expandable housingmembrane in one or more ways. For example, possible differences hereinin this context include, for example, one or more of chemical structure,durometer, stiffness, and thickness. For example, an overlay isconsidered different than a conduit membrane in this context if theoverlay is the same material as a membrane, but has a differentdurometer. Additionally, for example, an overlay is considered differentthan a impeller housing membrane in this context if the overlay is thesame material as a membrane, but has a different thickness than themembrane.

In any of the embodiments herein, an overlay may comprise a polymericmaterial, optionally a urethane, and optionally polycarbonate based. Inany of the embodiments herein, a membrane that at least partiallydefines a blood flow lumen may comprise a polymeric material, optionallya urethane, and optionally polycarbonate based. In any of theembodiments herein, the membrane may have the same chemical structure asthe overlay.

FIG. 31 illustrates an exemplary embodiment in which a sensor wire lumen1778 is not defined by a separate structural sensor wire housing, suchas in the embodiment of FIG. 30. In the example of FIG. 31, lumen 1778is defined by a combination of overlay 1777 and the expandable housing1775. By way of example only, the sensor wire lumen in FIG. 31 may becreated by creating a pump portion as shown in FIG. 30 (whether thesensor wire 1772 has been positioned as shown or not), and then removingthe sensor wire housing to thereby create lumen 1778 now defined byoverlay 1777 and the expandable housing 1775. In some embodiments theoverlay may comprise one or more polymeric materials, and the wire lumenmay be defined by one or more polymeric materials. Expandable housing1775 may, again, include any feature of any expandable housing herein,such as a membrane, an expandable support member, and impeller, etc.,exemplary details of which can be found elsewhere herein. Sensor wire1776 is shown floating in lumen 1778.

FIG. 32 illustrates an exemplary cross section of an embodiment of anexpandable housing 1780 (again, impeller not shown for clarity) thatincludes sensor wire 1782 floating within lumen 1781, wherein lumen 1781has a non-circular cross section. In this embodiment, the cross sectionis rectilinear (e.g., rectangular, square). The cross section can becreated by first positioning a rectilinear structure element over theexpandable housing 1780, then removing it after overlay 1783 has beendeposited on top of it, similar to the description of FIG. 31. Lumen1781 may be also defined by a sensor wire housing structural member thatis secured with overlay 1783.

FIG. 33 is a side view of a pump portion that includes an exemplaryexpandable impeller housing 1780 that includes sensor 1782 coupled tothe expandable housing 1780, and sensor wire lumen 1784 (and a sensorwire therein) extending in a linear configuration along the expandablehousing. Sensor wire lumen 1784 may be any of the wire lumens herein.

Expandable impeller housing 1780 may be any of the expandable housingsherein, including any that include more the one impeller, and any thatinclude one or more expandable support members that help providestructural support to the expandable housing.

In FIG. 33, sensor 1782 (which may be a pressure sensor) is secured to adistal strut 1786 of the expandable housing, wherein the strut is nearthe inflow of the pump portion. Strut 1786 may be any of the strutsdescribed herein or in any reference incorporated herein by reference.The sensors herein may be directly or indirectly secured to one or moreexpandable portion reinforcing elements (e.g., a struts, or an elementof a scaffold). In this embodiment, the sensor is secured to an element(e.g., a strut) extending radially inward relative to a portion of theexpandable housing at least partially surrounding an impeller. Any ofthe sensors herein can be coupled to an element with this configuration.

In this embodiment (and any embodiment herein), the sensor may besecured such that a pressure sensitive area of the sensor is notorthogonal to a longitudinal axis of the expandable housing, and isoptionally between 1 and 89 degrees relative to the longitudinal axis,such as from 5-85 degrees, such as from 10-80 degrees. The referenceangle theta is shows in FIG. 33.

In any of the embodiments herein, the sensor wire extends along theexpandable housing and is in communication with a proximal region of theblood pump that is spaced to remain outside of a patient when theimpeller is in use. Information sensed from the one or more sensors canbe used for one or more of the following: estimating flow, and detectingthe position of the blood pump. Additionally, one or more sensors may beaxially spaced apart (e.g., one near an inflow and one near an outflow,not shown), and used to determine a differential pressure across thepump portion.

FIG. 34A illustrates a distal region of an exemplary pump portion 1050showing collapsible blood conduit 1051 in an expanded configuration. Theinflow to the blood conduit is shown, and an optional distal impeller isnot shown. The blood conduit 1051 may comprise any aspect of any of theexpandable and collapsible blood conduits herein, including for example,any of one or more scaffolds, any of the one or more baskets, and any ofthe one or more membranes secured thereto. Pump portion 1050 includesdistal struts 1052, in this example four, but more or fewer may beincluded. Distal struts 1052 may be unitary or connected with a scaffoldof the blood conduit 1051, and are shown extending distally therefromand radially inward towards a distal hub or radially central region,which may include a distal bearing housing 1090 and one or more othercomponents 1080 that are included in a distal end region of the pumpportion.

In this example, and which is similar to embodiments above that includea distal sensor, sensor components are secured relative to one of thedistral struts 1052. Pump portion 1050 includes a sensor connectionhousing 1060 extending along the blood conduit and along one of thedistal struts 1052 as shown. Sensor connection housing 1060 may be anysensor connection housing herein that may house therein one or moresensor connections (e.g., wires) that are coupled to a distal sensor1072 and communicate information sensed therewith. The one or moresensor connections may extend all the way proximally through the pumpcatheter to an external console that is adapted to receive signalscommunicated along the sensor connections, such as signals indicative ofpressure sensed from the pressure sensor. Sensor connection housing 1060in this embodiment extends distal to the one or more impellers, andcontinues to a location 1074 where it meets sensor housing 1070. Sensorhousing 1070 is sized and configured to receive sensor 1072 at leastpartially therein. Sensor 1072 may be, for example, a pressure sensor.

Sensing housing or carrier 1070 is secured distal to the one or moreimpellers, and is secured to the distal end region of the pump portion,such as to a hub or other centrally located component 1080. In thisexample, distal struts 1052 have distal ends that are coupled to thedistal end region, such as to distal end hub component 1080.

In this example, as shown, sensor 1072 has a pressure sensitive face1071 that faces radially outward, in a direction orthogonal to a longaxis of the pump portion 1050, such that it is facing blood flowing pastsensor 1072 towards the inflow of blood conduit 1051.

Sensor housing 1070 may have a channel or depressed region formedtherein that is sized and configured to receive sensor 1072 therein andoptionally any distal regions of connectors (e.g., wires) that arecoupled to and in communication with sensor 1072, such as any of thewires herein extending along the blood conduit. An encapsulatingmaterial such as silicone may be deposited at least partially about thesensor 1072 and into the channel or depression in the housing toencapsulate the sensor 1072 relative to housing 1072 and help securesensor 1072 to housing 1070. Housing 1070 also functional acts as a baseto help stabilize the sensor relative to the pump. The central component1080 is considered to be an axially extending component with a radiallyoutward surface, and housing 1070 may be secured relative thereto sothat sensor 1072 faces outward as is shown. A pressure sensor facingoutward as shown and secured near the outflow to an axially extendingcomponent may provide more accurate pressure sensor readings near theinflow.

FIG. 34B illustrates an exemplary top view of a distal region of sensorhousing or carrier 1070 that may be incorporated into the pump design ofFIG. 34A. Carrier 1070 includes a channel or recessed depression 1073formed in a main housing body 1075. Sensor 1072 and associatedconnectors one or more connectors 1074 (e.g., wires) are shown diposedwithin the channel or recessed region 1073 therein. As set forth above,an encapsulating material may be disposed about the sensor 1072 and/orassociated one or more connectors 1074, such as in the volume betweenthe sensor 1072 and the channel or recessed depression 1073 formed inbody 1075 to help stabilize the sensor relative to the body portion ofthe housing.

1-12. (canceled)
 13. An intravascular blood pump, comprising: a pumpportion that includes a collapsible blood conduit; a plurality of distalstruts extending distally from the collapsible blood conduit, whereindistal ends of the distal struts are secured to a distal end portion ofthe pump portion that is disposed about a long axis of the pump portion,the collapsible blood conduit having an expanded configuration with aradially outermost dimension greater than a radially outermost dimensionof the distal end portion; a pressure sensor secured to the distal endportion, the pressure sensor having a pressure sensitive regionpositioned such that it is exposed to a flow of blood moving toward aninflow of the pump portion; and one or more collapsible impellers atleast partially disposed within the collapsible blood conduit.
 14. Theblood pump of claim 13, further comprising a pressure sensor connectorcoupled to the sensor and in communication with the pressure sensor,wherein the pressure sensor connector extends proximally from thepressure sensor and is coupled to a first strut of the plurality ofdistal struts.
 15. The blood pump of claim 14, wherein the pressuresensor connector comprises a wire.
 16. The blood pump of claim 15,wherein the pressure sensor connector is coupled to a radially outersurface of the first strut.
 17. The blood pump of claim 16, furthercomprising a pressure sensor connector housing in which the pressuresensor connector is disposed, the pressure sensor connector housingcoupled to the radially outer surface of the first strut.
 18. The bloodpump of claim 14, wherein the pressure sensor connector is coupled to aradially inner surface of the first strut.
 19. The blood pump of claim18, further comprising a pressure sensor connector housing in which thepressure sensor connector is disposed, the pressure sensor connectorhousing coupled to the radially inner surface of the first strut. 20.The blood pump of claim 14, further comprising a pressure sensorconnector housing coupled to the first strut, the pressure sensorconnector disposed within the pressure sensor connector housing.
 21. Theblood pump of claim 14, wherein the pressure sensor connector is securedto the first strut such that the pressure sensor connector is configuredto move towards a collapsed state when the blood conduit is collapsed,wherein the sensor is secured to the distal end portion and does notmove radially when the blood conduit is collapsed to a collapsedconfiguration.
 22. The blood pump of claim 13, wherein pressuresensitive face is facing radially outward in a direction orthogonal to along axis of the pump portion.
 23. The blood pump of claim 13, furthercomprising a pressure sensor housing in which at least a portion of thepressure sensor is disposed, the pressure sensor housing secured to thedistal end portion.
 24. The blood pump of claim 13, wherein the pressuresensor the distal end portion comprises a distal bearing housing that isdisposed distal to the blood conduit.
 25. The blood pump of claim 13,wherein the pressure sensor is coupled to a cylindrical component. 26.The blood pump of claim 13, further comprising a collapsible impellerhousing comprising the collapsible blood conduit and the plurality ofstruts, wherein a pressure sensitive surface of the pressure sensor isdisposed axially and radially outside of the collapsible impellerhousing.